Swing states across the American electoral map repudiated Republican candidates for the United States Senate Tuesday, sending many to defeat and allowing Democrats to strengthen their hold on the nation’s upper legislative chamber. One of the major arguments across key races was over the future of America’s tax code and whether the wealthy needed to pay their fair share or, in some instances, if they should instead receive another tax cut.

Here are four GOP Senate candidates who lost the argument over taxes last night:

1. Sen. Scott Brown — Massachusetts: Massachusetts’ junior senator lost his race to Harvard professor Elizabeth Warren (D) after being repeatedly hit for his opposition to raising taxes on millionaires and for his opposition to a payroll tax cut extension that would have largely benefited the middle class. Taxes were the “sharpest difference” between the two, according to the Boston Globe, and Warren ran ads against Brown’s filibuster of the payroll tax cut extension and in debates tied him to Grover Norquist, the anti-tax activist who authored a radical no-taxes pledge. While Brown opposed raising taxes on the wealthy, that policy was a “central plank” of the victorious Warren’s campaign.

2. Linda McMahon — Connecticut: McMahon, a former professional wrestling executive, released a tax plan that was virtually identical to presidential nominee Mitt Romney’s. And like Romney, McMahon pitched her plan as a tax cut for the middle class even as it provided massive tax breaks to the wealthy and corporations. McMahon often misrepresented the details of that plan, particularly when her opponent, Rep. Chris Murphy (D), challenged her in debates.

3. Tommy Thompson — Wisconsin: Thomspon also faced criticism from his opponent, Rep. Tammy Baldwin (D), for his support of Norquist’s tax pledge, which he seemed to misunderstand in one debate when he stated that it did not prohibit increasing taxes on the wealthy. While Baldwin was a sponsor of the Buffett Rule, President Obama’s plan to institute a minimum tax on millionaires, Thompson supported new tax cuts for the rich.

4. Josh Mandel — Ohio: Sen. Sherrod Brown (D) repeatedly hit Mandel for his support of Norquist’s tax pledge. “Signing a pledge to a fat-cat lobbyist like Grover Norquist is essentially giving away your right to think,” Brown said to Mandel during one of their debates. Mandel called for the elimination of the estate tax and reductions in investment and corporate tax rates, both giveaways to the rich. Mandel also called for a “flatter, fairer” tax code, the type of change that would almost surely raise taxes on low- and middle-income voters while giving the rich a huge tax cut.

Ohio Republican Senate candidate Josh Mandel, who is running to unseat Sen. Sherrod Brown (D), couldn’t name his position on the auto bailout during an interview with the Youngstown Vindicator, despite being asked half a dozen times in a number of ways.

In the interview with the paper’s editorial board, Mandel continually said he would have “had trouble” supporting the rescue plan because workers at Delphi, a local factory, lost some of their pension and health benefits as part of the package. But Mandel struggled to ever enumerate an actual position on the vote when asked for a yes or no answer.

“As the grandson of a UAW worker, I will do everything I can in the United States Senate to protect auto jobs,” Mandel said. “But it needs to done under the umbrella of the free enterprise system, without the federal government picking winners and losers. And it needs to be done in a way without stripping these hardworking workers of their pensions.”

Watch Mandel’s full answer:

Mandel also struggled to answer the question in an interview with the Columbus Dispatch, though he did manage to call Brown’s support for the rescue “un-American.” Those comments drew fire from the United Auto Workers, whose president said Mandel’s comments were “out of a cartoon or something.”

And though Mandel, like Republican presidential nominee Mitt Romney, may wish the free enterprise system could have saved the auto industry, the facts belie the argument. The private sector was unwilling to provide General Motors and Chrysler with the loans they needed to enter a managed bankruptcy, leaving government intervention as the only path available. According to at least one auto industry estimate, the auto industry’s rescue saved at least one million American jobs.