The common narrative asserts that a chasm separates Republicans like Bobby Schilling, of Colona, from Democrats like U.S. Rep. Cheri Bustos, D-East Moline.
But ahead of an election rematch campaign that will paint them as polar opposites, it's worth pointing out that they share many of the same policy positions.
They both are leery of major cutbacks in defense spending.
They agree on some of the key provisions in Obamacare and oppose others, like the medical device tax.
They think something needs to be done about the dizzying rise in the cost of college but struggle to provide a convincing solution.
They share concerns about the National Security Agency's all-encompassing intelligence-gathering machinery.
And they both describe themselves as belonging to what they perceive as the center of the political spectrum, even as they cast each other as "extremists."
The Affordable Care Act
A major theme of the campaign between the two will be the Affordable Care Act, popularly known as "Obamacare."
Mr. Schilling calls President Barack Obama's signature health care law a "complete disaster" yet he supports some of its key provisions.
The law allows adults to stay on their parents' plans until age 26 and has stopped insurers from denying coverage for people with chronic illnesses like diabetes.
Mr. Schilling supports those reforms, as does Rep. Bustos.
Since being elected in 2012, Rep. Bustos has carried the fight started by Mr. Schilling when he was in Congress against the medical device tax created by the Affordable Care Act.
Both have failed in their effort to stop the tax, which was introduced on Jan. 1, 2013, as one of the law's funding mechanisms.
They have both stated that the tax threatens jobs at medical device manufacturer Cook Medical Inc. in Canton.
The tax applies to clinical medical devices used by hospitals such as defibrillators and CAT Scan machines. It does not apply to devices purchased by ordinary consumers such as hearing aids or wheelchairs.
Rep. Bustos does not talk about "Obamacare" in the sort of apocalyptic tones used by Mr. Schilling.
"Throughout the country we have millions of people who did not have health insurance who now do," she said.
At the same time, she won't say if she regards the law as a success.
By the March 31 open enrollment deadline, 7 million Americans had signed up for the new health insurance options created by the law, according to the White House.
Mr. Schilling argues that the law has not addressed the issue of cost in the health care system.
He says fewer regulations would decrease costs and wants doctors to be allowed to write off charitable care on their taxes.
Another issue where's there's little daylight between Rep. Bustos and Mr. Schilling is defense spending.
Both are ardent supporters of the Rock Island Arsenal as the region's largest employer.
Mr. Schilling regards cutbacks in defense and the proposal from Secretary of Defense Chuck Hagel to reduce the size of the military as changes that would make America "vulnerable."
"If you take a look at what's happening with our military right now, I believe that we've been put into a very dangerous position," Mr. Schilling said.
But the kind of major cutbacks Mr. Schilling fears have not yet moved beyond the discussion stage and may never happen.
The mini-budget passed in December with bipartisan support and backed by Rep. Bustos restored $30 billion in defense spending that was due to be cut.
Meanwhile Sec. Hagel's proposal to reduce the active-duty Army personnel from 520,000 now to 440,000 faces an uphill battle in Congress.
And the U.S. remains massively ahead of any other nation in terms of defense spending.
In an interview Friday, Rep. Bustos would not say if she thought the defense budget is too big, too small or about right.
"I will keep fighting for the Arsenal; that's my answer," she said.
Congress has been rocked by revelations from Edward Snowden that have revealed the extent of the NSA's huge intelligence gathering systems.
Mr. Snowden was a contractor for the NSA before he left the country and began leaking NSA documents to the media.
The leaks revealed that the government is scooping up massive amounts of information about the activities of Americans, from text messages to internet searches.
Mr. Schilling views the NSA spying techniques as potentially unconstitutional. The constitution forbids the quartering of troops in private homes without permission.
"With what they're doing right now, they're quartered in our house, that's what I believe and that needs to be addressed swiftly," Mr. Schilling said.
"It's Big Brother coming in and basically knowing everything they can about us as individuals."
He believes Mr. Snowden is a patriot and should not be punished for the leaks.
Rep. Bustos shares concerns about intelligence gathering but does not overtly criticize the NSA.
"I think there have been some examples that have come out that have been concerning but at the same time we are still living in a post-9/11 world," she said.
As for Mr. Snowden, who is in Russia, Rep. Bustos said it was up to law enforcement agencies to decide his fate.
Mr. Schilling and Rep. Bustos both will campaign on the need to expand opportunities for children from middle and lower class families.
They see education as the best way to reduce inequality and improve the economy. But the soaring cost of attending college undercuts that argument.
The average cost of tuition at public four-year colleges and universities in Illinois has risen 21.1 percent between 2008 and 2013 alone, according to the nonpartisan Center on Budget and Policy Priorities.
"I don't know what the answer is to fix the cost of college going up," Mr. Schilling said.
Rep. Bustos said she would continue to "fight to keep interest rates on student loans low" and opposes cutbacks in Pell Grants.
But she understands that neither goal is likely to reverse the trend of rising tuition prices.
Mr. Schilling offered two ideas that he said could help.
Increasing Pell Grants, he said, only seemed to encourage colleges to increase their prices for students. As a nation, he added, we need to move away from the idea that "every kid should go to college."
The middle class
The rising cost of college is in stark contrast to the stagnant wages experienced by middle class families for more than a decade.
Between between 2000 and 2012, wages were flat or declined for the entire bottom 60 percent of the wage distribution, according to the non-partisan Economic Policy Institute.
The question of what to do about that problem will be key in this year's election and is an issue on which there are big differences between Mr. Schilling and Rep. Bustos.
For Mr. Schilling the answer is simple.
"Get the government off the back of small businesses," he said.
He's also adamantly opposed to raising the minimum wage as way to lift wages.
Rep. Bustos supports a proposal from President Obama that would increase the federal minimum wage to $10.10 an hour, from $7.25 now. In Illinois the minimum wage is $8.25.
"There should not be people out there who put in a hard day's work, who work 40 hours a week and live in poverty," Rep. Bustos said.
But for Mr. Schilling such statements come from people who in his view don't understand how businesses operate.
Raising the minimum wage will cut jobs and raise prices, he said. His own pizzeria would have to close if the minimum wage is increased to $10.10, he added.
The Congressional Budge Office found that a $10.10 minimum wage would result in between zero and 1 million jobs losses.
The CBO then split the difference to estimate 500,000 jobs could be lost in its report on President Obama's proposal. On the other hand, the increase would raise wages for 16 million Americans and lift 900,000 out of poverty, according to the CBO.
The campaign between Rep. Bustos and Mr. Schilling is again likely to be very expensive.
In 2012, the 17th Congressional District race between the two saw spending of close to $14 million, including $9.2 million in spending by outside groups.
Rep. Bustos already has raised $1.2 million for this year's campaign, according to the Federal Election Commission. Mr. Schilling has banked $327,000.
The 2012 election saw Rep. Bustos win by a healthy margin of 53.3 percent to Mr. Schilling's 46.7 percent.
But this year's election is likely to be more competitive because it's a mid-term, which usually produces a smaller turnout that's more favorable to Republicans.
Independent voters could be crucial to the outcome.
Perhaps with this in mind, both candidates are seeking to position themselves in what they see as the center of the political spectrum.
Rep. Bustos recently joined the Blue Dog caucus, which is regarded as the conservative faction within the Democratic Party.
Meanwhile, Mr. Schilling's favorite line is that issues are not "Democrat or Republican" but "red, white and blue."
When he was in office, Mr. Schilling joined a bipartisan group called No Labels.
The organization describes itself as a "movement of Democrats, Republicans and independents dedicated to promoting a new politics of problem solving."
Soon after taking office, Rep. Bustos also chose to join No Labels.
The 17th Congressional District runs from Peoria in the south to Freeport in the north and includes Rock Island, Henry and Mercer counties. It leans Democratic. The general election is Nov. 4.
The candidates in brief
Age: 53 City: East Moline Occupation: U. S. Representative for 17th District. Former vice president of communications and public relations for Trinity Regional Health System and its parent organization Education: University of Maryland and the University of Illinois at Springfield Family: Married with three sons Party: Democrat Political experience: East Moline 4th Ward alderman, 2007-2011 Website: cheribustos.com Social networking: Facebook.com/CheriBustosForCongress, Twitter (@cheribustos)
Party: Republican City: Colona Age: 50 Family: married, 10 children Occupation: Owner of St. Giuseppe's Pizza in Moline, U. S. Representative from 17th District, 2010-2012 Political experience: Elected to Congress in 2010 Education: Alleman High School graduate and attended Black Hawk College Website:reelectbobby.com Social media: facebook.com/BobbySchilling17