Their solidarity as two disabled members of Congress was evident on a cold January day in 2013. New Hoffman Estates Democratic congresswoman Tammy Duckworth, a double-amputee Iraq War veteran, climbed 15 of the Senate steps with two prosthetic legs, then stood without a handrail for more than a half-hour. She was waiting for Republican Mark Kirk, Illinois' junior senator from Highland Park, to make his triumphant ascent to the upper chamber for the first time since his stroke a year earlier.
"I was there," she later told the Daily Herald, "to support the senator, but I thought it was an important illustration of what you can truly do with your life."
Three years later, Kirk and Duckworth are facing one another in a heated and often nasty nationally watched race that could help decide which party gets control of the Senate.
Kirk has accused Duckworth, a former head of the Illinois Department of Veterans' Affairs, of "putting political ambition before veterans" in a commercial. Duckworth, meanwhile, has attacked Kirk, a former Naval reservist, for past exaggerations of his military record.
An increasing amount of money spent on key races in Illinois, as well as the polarized nature of political primaries, makes it unlikely that Kirk and Duckworth, or for that matter, other once-friendly opponents, could fully return to that previous supportive relationship.
"Can (House Speaker) Paul Ryan work with Hillary Clinton if she wins the presidency? No. Because the Republican primary voters will not let that happen," said Tom Bowen, a Chicago-based political strategist.
"On the state level, the idea that Republicans and Democrats can work together is a fantasy, given the current state of things."
Illinois, which has a multibillion-dollar bill backlog, has gone without a full-year budget since July 1, 2015. After more than a year of failed negotiations, a stopgap plan was approved this summer to fund operational expenses through January.
Aiding the impasse are the millions of dollars that can now be funneled to state legislative candidates on both sides of the aisle as they bid for re-election.
Even President Barack Obama acknowledged the increasing polarization of politics in a recent New Yorker interview with Jonathan Chait.
"I think one way of measuring my approach is that when I was in the Illinois legislature, I famously got along with the Republicans there ... so much that I was actually using some of my Republican colleagues in ads when I started running for president."
These days, he told Chait, it's different. "The problem hasn't been personal interactions," Obama said. "The conversations I have privately with Republicans are always very different from the public presentations that are made of them."
Former state Sen. Kirk Dillard, a Hinsdale Republican, was one of those Republican senators featured in the Obama ad. The commercial became a line of attack from opponents when Dillard made a 2014 primary bid for governor.
"Part of it is just style," Dillard said. "It's also how I believe I was able to accomplish a lot as a state senator in a Democratic-controlled state. It's by having the mutual respect of Democrats as well as blocks of minority members that would vote for my legislation."
However, he said, he believes an increasing number of political blogs, high-pitched political coverage on cable television as well as an increasing amount of outside spending from political action committees "has a lot to do with the nastier tone of American campaigns."
For example, the race for 20th District Illinois House, which includes portions of Rosemont, Des Plaines and Park Ridge, between 20-year incumbent Michael McAuliffe, a Chicago Republican, and Chicago Democrat Merry Marwig is now considered to be the most expensive state legislative race in the nation, according to the Center for Public Integrity, with more than $4.1 million spent so far.
Ultimately, Dillard said, that money will work to thwart the independence of the eventual victor -- and the ability to get along with the other side.
"The amount of money on both sides in that race, no matter who wins that race, will make it very difficult for the winner of that race not to toe the line of their political party or whoever was paying for those ads. When you need that kind of money to win it's very difficult to break from the folks who paid for your campaign. And that's not the way you should legislate."