GOP primaries

"If he carries Ohio it's going to sew it up for Mitt Romney," the Republican said ahead of the votes.

The controversy surrounding Rush Limbaugh's recent remarks that a graduate student who testified before Congress in favor of President Obama's contraception mandate was a "slut" might have been more than a minor distraction for Rick Santorum, who needed to pivot away from social issues to focus on economic matters this week.

Professor Paul Beck of the Ohio State University told The Hill that Limbaugh's controversial remarks might have hampered Santorum, who hurt himself heading into last week's primary in Michigan by focusing too much on social issues.

"There is this perceived extremity from Santorum on some of the social-conservative issues, which may be more salient now because of the Limbaugh flap and how people have reacted to that," Beck said.

Santorum called Limbaugh's remarks "absurd," but said that "an entertainer can be absurd."

After Limbaugh initially defended his remarks, a number of companies pulled advertising from his show. He apologized for the comments over the weekend.

Mitt Romney alleged Monday that President Obama is living in “an imaginary world where government-subsidized windmills and solar panels could power the economy.”

Romney, in an op-ed in the Columbus Dispatch, appealed to Ohio voters facing soaring gas prices. The op-ed comes a day before the state’s primary, where Romney and rival Rick Santorum are in a dead heat.

The GOP White House hopefuls have consistently blamed the president for high gas prices in recent weeks, arguing that the administration has stood in the way of a major expansion of domestic oil-and-gas drilling.

Romney is appearing in an ad for Sen. Orrin Hatch and an outside spending group is spending on Hatch's behalf

Restore Our Future, a super-PAC backing Mitt Romney for president, has doubled its television ad buys in four big Super Tuesday states, Georgia, Ohio, Oklahoma and Tennessee, a group spokesman told The Hill.

The states are four of the largest to vote next Tuesday, and in all four states Romney is the underdog or in a tough race. He hopes to win Ohio, the key state on Super Tuesday, where he is in a tight race with Rick Santorum, and pick up some delegates in the other states.

House Speaker John Boehner (R-Ohio) praised Rep. Fred Upton (R-Mich.), the chairman of the House Energy and Commerce Committee who is facing a potentially tough Tea Party primary challenge.

Upton has a relatively centrist voting record, although it has trended more conservative in recent years. He is facing a rematch against former state Rep. Jack Hoogendyk (R), who held him to 57 percent of the primary vote in 2010 despite spending almost no money on the race.

The deep-pocketed, fiscally conservative Club for Growth has already run TV ads slamming Upton's record, and could spend heavily on the race.

"Well, I don't know much about what the Club for Growth is doing, but I can say this: Chairman Upton has done a marvelous job as chairman of the Energy and Commerce Committee, led the effort to repeal ObamaCare, led the effort to expose the Solyndra, and he's got as conservative a voting record as — as you'll find," Boehner said on Thursday in response to a question about the Club for Growth's attacks. "Frankly, I think he's done a marvelous job on behalf of Republicans here in the House."

Boehner's support could be a big boon to Upton, especially if he decides to help him with fundraising.

The numbers indicate he could be close to achieving financial parity with Mitt Romney.

Former Wisconsin Gov. Tommy Thompson (R) released his first television ad of the cycle, a spot attacking President Obama, on the same day a new poll showed him dominating his primary rivals and within one point of Rep. Tammy Baldwin (D-Wis.) in a general-election matchup.

Thompson almost doubles up the support for his primary opponents, former Rep. Mark Neumann (R-Wis.) and Wisconsin state Speaker Jeff Fitzgerald. Thompson is at 39 percent in the poll, conducted by the Democratic Public Policy Polling, while Neumann and Fitzgerald each are at 22 percent.

Top conservative and Tea Party groups including The Club for Growth, RedState.com's Erick Erickson and Sen. Jim DeMint's (R-S.C.) Senate Conservatives Fund have  endorsed Neumann, and many conservatives have issues with Thompson. But Neumann is also disliked by some Wisconsin conservatives because of lingering tensions from his primary against now-Wisconsin Gov. Scott Walker (R), who is close to Fitzgerald. The poll indicates the two are splitting the anti-Thompson vote, which could hand him a primary win.

Thompson is widely believed to be Republicans' best shot at winning the race, a perception the poll confirms.

Ron Paul is out with a new ad slamming all three of his primary opponents and describes Mitt Romney as a "flip-flopper who has been on all sides."

"We didn't win by a lot but we won by enough, and that's all that counts," Mitt Romney said.