An endorsement by a former one-term lieutenant governor who has been out of office for a decade ordinarily wouldn’t hold much significance in a primary campaign for U.S. Senate.

But an endorsement from Sheila Simon might be a slight exception. Not because of the ex-lieutenant governor‘s individual political influence, but because, even as the Democratic voter base in downstate Illinois is ever-shrinking, her support highlights that statewide candidates must still spend considerable time and energy wooing party members far from deep-blue Cook County.

That’s become particularly true in the Democratic Party’s Senate primary campaign. All three major candidates in the race are from the Chicago region and are running to succeed retiring U.S. Sen. Dick Durbin of Springfield, who for the last 28 years has balanced an upstate-downstate split in Illinois’ Senate representation.

Although ballots cast outside the six-county Chicago region accounted for less than a quarter of the overall vote in the past two contested Democratic Senate primaries, in 2010 and 2016, the announcement last week that Simon was backing U.S. Rep. Raja Krishnamoorthi‘s candidacy serves as a reminder that all three top-tier candidates in the March 17 primary know building credibility beyond Chicago and its increasingly Democratic suburbs is essential.

Simon’s backing does, of course, carry some modest political weight. Now a law professor at Southern Illinois University in Carbondale, she’s the daughter of the late U.S. Sen. Paul Simon, the man Durbin replaced in the Senate in 1997. She also remains a recognizable and well-connected figure in a region where her family name is tied to the identity and history of local Democratic politics.

Coming out on top of a primary field that currently stands at 14 candidates will require building a coalition of support that extends beyond Chicago and Cook County, said John Jackson, a visiting professor at SIU’s Paul Simon Public Policy Institute.

That’s a big part of the reason the top three candidates have played up their downstate bona fides, Jackson said.

For both Krishnamoorthi, of northwest suburban Schaumburg, and Rep. Robin Kelly, of south suburban Lynwood, that means emphasizing their Peoria roots: his upbringing in an immigrant family there and her time at Bradley University and two decades, on and off, spent living in the central Illinois river city. Kelly also points to the makeup of her current congressional district, which stretches from Chicago’s South Side to Danville in east-central Illinois.

A South Side native, Lt. Gov. Juliana Stratton leans on her two terms in statewide office alongside Gov. JB Pritzker, particularly her role leading the Governor’s Rural Affairs Council, and her education at the University of Illinois at Urbana-Champaign.

One thing that can help distinguish a candidate, particularly in parts of the state that often feel overlooked or forgotten, is face time with voters, Jackson said.

“People want to be — especially (party) activists — want to be talked to,” Jackson said. “They want people (running for office) to show up.”

Even in the age of social media algorithms, TV advertising also remains an important tool for candidates to become familiar to voters.

With several visits to Carbondale and other communities in the region this year and TV ads airing on multiple networks since summer, including on affiliates based out of nearby Kentucky and Missouri, Krishnamoorthi has built an advantage, at least in that corner of southern Illinois, “that’s going to be hard for the other two to match,” Jackson said.

Building a strong base of support downstate in the early stages of the campaign allows candidates to focus more attention and resources on Chicago and its voter-rich suburbs as primary day gets closer. It has possibly become even more important with the rise of early voting, both in person and by mail. Voters actually will start casting ballots during the first week of February.

In the state’s closest Democratic Senate primary in recent memory, then-Illinois Treasurer Alexi Giannoulias in 2010 topped a field of five candidates.

Giannoulias, who lost the general election that November to Republican Mark Kirk of Highland Park, won his party’s primary by 5 percentage points over his nearest competitor, former federal prosecutor and Chicago Inspector General David Hoffman.

Giannoulias’ margin of victory was padded by a strong showing outside Cook County and the five collar counties. While he won the Chicago area vote by 2 percentage points, he took the downstate vote by nearly 16 points.

This year, “if it’s close enough, especially in a three-candidate race, downstate could be a factor,” said Dan Shomon, a lobbyist and political consultant who was campaign manager and political director for Barack Obama’s 2004 U.S. Senate run. The host of lesser-known candidates on the ballot could further split the vote.

To shore up support outside the Chicago area, “it’s important … that you’re there, you’re there early and you’re there often,” said Shomon, who isn’t working with any of the current Senate candidates but has contributed $1,000 each to Krishnamoorthi’s campaign fund and a Stratton-affiliated political action committee.

In 2004, Obama, a state senator from Chicago, lost the downstate vote in the Democratic primary by nearly 16 percentage points to the better-connected, better-funded campaign of then-Illinois Comptroller Dan Hynes. But the time Obama spent downstate, going back to a 1997 trip to southern Illinois when he was a freshman state lawmaker, helped him outperform expectations, garnering just over a quarter of the vote outside Cook and the collar counties in the Senate primary, Shomon said.

For Krishnamoorthi, the recent endorsement is “important because of the Simon credibility factor,” Shomon said. And the amount of time Krishnamoorthi, a five-term congressman, has spent building support far from his home base in the northwest suburbs “makes a huge difference,” Shomon said.

“It also shows that a candidate who’s Asian American can get votes in areas where there’s very few Asian Americans,” he said.

Stratton also “has spent a significant amount of time downstate,” Shomon said.

Indeed, while Krishnamoorthi has made his central Illinois roots a central theme, launching his campaign in front of his childhood home in Peoria, and has traversed the state for many months, including an eight-stop downstate listening tour over the summer that brought him to Simon’s Carbondale home, neither of the other major candidates is conceding the downstate vote.

Stratton, who was the first candidate to officially enter the race, has made campaign stops from Rockford to Murphysboro and from Alton to Champaign-Urbana.

Like Krishnamoorthi, the two-term lieutenant governor has focused on securing endorsements from downstate Democratic Party chairs, whose support can bring on-the-ground manpower.

Stratton has received the backing of local party chiefs in nine downstate counties, compared with 14 for Krishnamoorthi. Stratton’s backers include the chair in Jackson County, which includes Carbondale.

“In addition to campaign appearances across the state, the lieutenant governor has spent the last seven years traveling to communities in every corner of Illinois and meeting with Illinoisans in her official capacity,” campaign spokesperson Allison Janowski said in a statement. “She’s the only candidate who has represented the entire state, and she’s not a stranger to communities in southern, central, northwestern Illinois, or in the Greater Chicago region. They know her, they know her record, and she has delivered real results for their communities.”

That’s true for Brandi Bradley, chair of the Williamson County Democratic Party in far southern Illinois.

A former staffer for Durbin and southern Illinois U.S. Reps. Jerry Costello and Bill Enyart, Bradley has gotten to know Stratton over the years in her role as a local party leader. Bradley also has been the Pritzker-appointed Illinois designee to the multistate Delta Regional Authority, which supports economic development in the lower Mississippi River and Alabama Black Belt regions. She’s worked with Stratton in that capacity as well.

“She’s spent the time, and she’s listened,” Bradley said. “And so to me, it was an easy choice. It wasn’t just about a campaign. She knows our region well, and I’ve worked really well with her.”

While Krishnamoorthi and Kelly have congressional experience, to represent a region in the Senate, “the core thing you have to have is an understanding of the area, the issues and a love for the people, and then you can represent them in Washington well,” Bradley said. Stratton’s “experience with the state and working the whole state is more valuable than someone that has been … working in Washington.”

Kelly, meanwhile, has focused her downstate campaigning in more populous areas such as Rockford, Springfield, Peoria, Champaign-Urbana, the Quad Cities and the Metro East region just across the Mississippi River from St. Louis. But she’s also made stops as far south as Carbondale and DuQuoin and hit smaller communities in central and western Illinois.

Kelly’s “people over profits” message, which includes supporting a $17-per-hour federal minimum wage, resonates with voters concerned about affordability across the state, including rural communities like those in her district, her campaign said.

That economic platform, which also includes a proposed minimum federal tax on individuals whose annual net worth exceeds $100 million, is an important part of Kelly’s appeal to state Rep. Carol Ammons, an Urbana Democrat who has endorsed the seven-term congresswoman.

The boundaries of Ammons’ Illinois House district and Kelly’s congressional district are about 12 miles apart, but the two have worked together on numerous legislative and political issues, and Kelly’s is a familiar face on the U. of I.’s flagship campus and in the broader Champaign-Urbana community, Ammons said.

In addition to knowing the needs of rural communities like those she represents in Congress, Kelly “knows how Washington works,” Ammons said. “She’s been there long enough to know how to get things done, and that experience is going to be extraordinarily invaluable in the moment that we’re in in D.C. and in the nation.”

For her part, Sheila Simon, who served alongside Gov. Pat Quinn from 2011 to 2015, is somewhat skeptical about how much influence her individual endorsement — even with its implicit attachment to her father’s legacy — will have on the outcome of the Senate primary.

Such endorsements “probably don’t carry a whole lot of weight at all, but maybe it causes a few people to pay some closer attention and to look into a candidate that they might have overlooked before. So that’s what I’m hoping for.”

Simon has known Krishnamoorthi since his unsuccessful primary campaign for state comptroller in 2010, the same year she was elected lieutenant governor alongside Quinn. When Krishnamoorthi came to speak at SIU’s law school early this year, before he jumped into the Senate race, Simon was impressed by the way the congressman connected with an audience that ranged from the Simon Institute’s John Jackson to Nick Wilhelm, the 15-year-old son of a colleague.

Simon also touted Krishnamoorthi’s ability to draw on his experience growing up in a family that for a time relied on federal public assistance to address the challenges facing low- and middle-income Illinois families today.

When Krishnamoorthi returned to Carbondale in July for a campaign event at Simon’s home, Nick Wilhelm was in attendance again, this time introducing the candidate to the small group.

Making that kind of connection with supporters far from home is key to running a statewide campaign, Simon said.

“The math adds up to spending a lot of time in the Chicago area because that’s where most of the primary voters are,” she said. “But my vote down here in Carbondale counts as much as anyone’s vote up in Chicago. … You need to be able to appeal to the state, and campaigns are part of the process of getting you ready to serve. And whoever is elected the next United States senator is going to be serving the whole state, and they’re going to be able to do a better job if they know the whole state, if they have someone they can call in every part.”