If you're searching for a Tea Party litmus test this year, look no further than Indiana's U.S. Senate race.
Tea Party-backed GOP state Treasurer Richard Mourdock is locked in a close race with House Democrat Joe Donnelly, who has represented Indiana's 2nd Congressional District since 2007.
How Mourdock got there is as interesting as the race itself. In a stunning primary upset in May, he knocked off Richard Lugar, the six-term GOP senator known for his willingness to cross the aisle on key issues. Mourdock immediately hit the TV news shows and proclaimed that "bipartisanship ought to consist of Democrats coming to the Republican point of view."
Mourdock's opponent is a conservative "Blue Dog" Democrat, and the two are not far apart on many issues. That has brought the issue of bipartisanship to the forefront, says Peri Arnold, a political science professor at the University of Notre Dame in South Bend, Ind. The latest poll shows the two candidates running neck and neck, with the edge to Donnelly.
Arnold says Republicans hoping to pick up enough seats next month to win control of the Senate risked a sure thing with Lugar and placed all their Tea Party chips on the campaign table with Mourdock. "My sense is that Lugar could have easily won the general election," he says.
Here's a side-by-side comparison of Mourdock, 60, and Donnelly, 57.
Candidates: Richard Mourdock // Joe Donnelly
Mourdock: Indiana state treasurer, 2007-present; county commissioner, Vanderburgh County Board of Commissioners, 1995-2002
Donnelly: U.S. House of Representatives, 2007-present
Mourdock: Recorded and accidentally uploaded to YouTube four possible responses to the Supreme Court's decision on President Obama's health care law before the decision was handed down. The gaffe inspired a Stephen Colbert parody.
Donnelly: Creating an ambitious "Republicans for Donnelly" drive that fizzled.
2012 Money Race
Mourdock: $4 million raised; $3 million spent as of June 30 (latest available data), with 12 percent coming from political action committees.
Donnelly: $2.6 million raised; $1.2 million spent as of June 30, with 32 percent coming from political action committees.
Mourdock: Opposes abortion. Believes Roe v. Wade "is a serious misreading of the Constitution." Has said he would support legal abortion in the case of some "crisis pregnancies."
Donnelly: Opposes abortion. National Right to Life Committee says, "Joe Donnelly supported the interests of the National Right to Life Committee 83 percent [of the time] in 2010."
Mourdock: Says he "oppose[s] restrictions on gun ownership by law-abiding citizens."
Donnelly: Says he supports the Second Amendment right to bear arms. Voted for a bill to establish a national standard for carrying of concealed firearms across state lines.
Mourdock: On MSNBC in May: "To me, the highlight of politics, frankly, is to inflict my opinion on someone else with a microphone or in front of a camera to win them over to my point of view." On Fox News: "I have a mindset that says bipartisanship ought to consist of Democrats coming to the Republican point of view." Has since indicated that he'll work with Democrats.
Donnelly: At an August appearance in Fort Wayne, Ind.: "We don't expect a my-way-or-the-highway attitude; we expect getting things done."
Mourdock: Has signed Grover Norquist's "Taxpayer Protection Pledge" vowing not to raise taxes.
Donnelly: Supports "responsible efforts to promote tax relief to help small businesses and middle-class families and keep our economy healthy," according to his campaign website.
Mourdock: Wife, Marilyn. He runs marathons and holds a pilot's license.
Donnelly: Two children with wife, Jill, whom he met while attending the University of Notre Dame.
Mourdock: Evangelical Christian
Donnelly: Roman Catholic
Mourdock: Masters in geology, Ball State University, 1975
Donnelly: Law degree from Notre Dame, 1981
Mourdock: Indiana state treasurer, 2006-present; co-founded Sub-Tech Environmental Services, a consulting business, 2000; vice president at Koester Companies (earth-moving equipment) in Evansville, Ind., 1984-2000; senior geologist, Standard Oil of Ohio, 1979-1984
Donnelly: Practiced law until 1996, when he opened Marking Solutions, a printing and rubber stamp company.