As one of just a handful of seriously competitive U.S. Senate races this cycle, it's no surprise that the campaign for Barack Obama's old seat has been a brutal one. Both major party nominees -- Democrat Alexi Giannoulias and Republican Mark Kirk -- have dragged their rival through the muck, calling into question the other's judgment on both ethical and political grounds.

The criticisms levied about the Republican nominee worry us greatly. Throughout the campaign, Mark Kirk has consistently inflated his resume, changed positions on several key issues, and taken in loads of contributions (some anonymously) from players on Wall Street and in the conservative elite. In short, we're not convinced that he will adequately represent all Illinois voters in the upper chamber. Below is our more detailed case:

The Lame Duck Session:

The winner of tomorrow's election is going to have an immediate impact in Washington. Because Illinois is holding a special election on Election Day to replace Sen. Roland Burris, Kirk could join the Senate as soon as November 3. According to the Republican, serving as the 42nd GOP vote during the so-called "lame duck" session this winter "is a game-changer."

What bills will the chamber debate after the election? The highest profile fight will be over the Bush-era tax cuts. Kirk wants to see the tax breaks extended to all Americans, including those who earn over $250,000 annually, even though it would blow a major hole in the national deficit. At the very least, he would vote for a two-year extension, which would still inflate the national debt considerably. (For what it's worth, only 32 percent of Illinois voters recently polled on the question thought the tax cuts should remain in place for all income levels.)

This weekend, Senate Majority Leader Harry Reid (D-NV) formally announced that the Senate will vote on the DREAM Act next month. Immigration reform advocates in Illinois are none too pleased with Kirk, who has said it's "not the time" to pass that piece of legislation, which would provide upstanding undocumented children a pathway to citizenship should they complete two years of college or military service. That position could spur turnout in the immigrant community tomorrow.

Unemployed workers statewide will be watching the race closely, as well. If the Senate doesn't get its act together, 127,767 Illinoisans will exhaust their unemployment benefits at the end of November. More will follow in the months ahead. This year, the North Shore Republican has consistently voted against emergency extensions. And one of his new "spending reform" proposals will mandate that any bill that would increase the deficit even by $1 would require super-majority support. That means he's almost assuredly a "No" vote on this issue.

The Exaggerations

Is Kirk a man of his word? Since winning the GOP's U.S. Senate primary, the candidate has been caught needlessly and repeatedly embellishing his resume: asserting falsely that the U.S. Navy once named him "intelligence officer of the year," that he came under enemy fire (or even served) in Iraq, that he "deployed" to Afghanistan while serving in Congress, that he never conducted partisan political activities while on active Navy duty, that he "commanded" the Pentagon war room, that he taught in a middle school after completing college, and that he convinced the entire Republican caucus to oppose President Obama's stimulus bill.

The local media, which has given him favorable coverage over the years, jumped all over the candidate's "hubris" and called out his defensive rebuttal that the embellishments were careless and accidental. Some went so far as to question if the North Shore Republican is fundamentally dishonest. Others dug through his history of false radio claims. Kirk responded by telling reporters he wouldn't discuss his resume going forward.

Voters have reacted with disgust. A poll conducted last month found that 41 percent of respondents, including 42 percent of independents, said they were less likely to support Kirk because of what MSNBC's Rachel Maddow called his "amazing, amazing stories:"

Shifting With The Wind ...

Like an acrobat, throughout the 2010 election season, Kirk flip-flopped on a number of critical issues.

It all started with his sudden and startling reversal on the cap-and-trade climate change bill that passed the House, with Kirk's vote, in 2009. The congressman received what he described as "a stronger reaction than I've ever seen before" from opponents of the legislation and soon after was insisting that he voted for the bill only to satisfy the "narrow interests" of his district. He won't support that bill should he be elected to the Senate. The Giannoulias campaign enlisted Sen. John Kerry (D-Massachusetts), an architect of the cap-and-trade bill in the Senate, to criticize Kirk for the flip flop.

A one-time advocate for gay rights, the GOP U.S. Senate candidate now opposes gay marriage, supports the Defense of Marriage Act, and voted against repealing the military's discriminatory "Don't Ask Don't Tell" policy.

In terms of the federal health care reform bill, throughout 2009 Kirk bashed the Democratic reform legislation. Two weeks before President Obama signed it into law, Kirk even promised a group of GOP supporters that he would "lead the effort" to repeal the package.

Once larger media outlets caught wind of his statement and legal experts and lawmakers across the country expressed skepticism that his repeal gambit was a logistical possibility, Kirk began to equivocate. During the week following the passage of the health care bill (which he voted against), the Republican dodged a series of questions on that topic from reporters. Then he modified his criticism to say that he would only oppose "the new taxes and Medicare cuts to pay for it," even though that stance was illogical and ignored completely how this bill works.

But over the summer, with the GOP facing pressure from conservatives to fight against President Obama's most important legislative achievement to date, Kirk appeared to begin renewing his support for a full repeal. In an interview with Chicago Public Radio, Kirk said he intends to sign a discharge petition -- which is a procedural method to force a vote in the House -- in favor of legislation introduced by Rep. Wally Herger (R-CA) that would repeal the new health care law.

Kirk has bragged about supporting high speed rail projects, but he didn't vote in the House for a mechanism to fund them. He opposed the stimulus bill -- which included $8 billion for high-speed rail nationwide -- and backed a July 2009 amendment to strip $3 billion in further rail funding from a broader transportation and housing bill. 

President Obama cut an advertisement for Giannoulias that pointed out Kirk's propensity to go in reverse from time and again. "He doesn't shift in the wind," the president said of Giannoulias. Watch it:

Kirk's Friends And Funders