Republicans seized control of the House of Representatives on Tuesday, gaining more than 50 seats, well ahead of the 39 needed for a majority. Although the Democrats retain control of the Senate, the GOP has captured at least six seats with gains in Indiana, Arkansas, South Dakota, Pennsylvania, Wisconsin and President Obama’s former Senate seat in Illinois. Republicans will now have enough votes to sustain any filibuster and forestall Obama’s legislative agenda and judicial appointments.

“It was not a good night for the Obama agenda,” said political science professor Gary Segura.

“These elections results were based not so much on what Obama focused on, but because his policies were too far to the left,” said Greg Hirshman ’11, editor of The Cardinal Principle.

In a measure of just how vulnerable Democratic incumbents were in the midterm elections, Senate Majority Leader Harry Reid of Nevada was in a tight contest that ended with a slim victory over tea party candidate Sharon Angle. Sen. Russ Feingold, Democrat of Wisconsin and a three-term incumbent, was defeated by newcomer Republican Ron Johnson. Fifteen-term incumbent Barney Frank, chairman of the powerful House Financial Services Committee and architect of the 2010 Dodd-Frank Wall Street Reform Act, prevailed in an unexpectedly tough challenge in his Massachusetts district from first-time Republican candidate Sean Bielat.

Many Democrats, however, remain hopeful that Obama will continue his agenda despite the power shift in the House.

“I don’t think that the strong showing by Republicans will significantly change the president’s agenda,” said Andy Parker ’11, president of the Stanford Democrats. “He is committed to getting the economy on track, creating jobs and taking action on issues such as climate change and immigration.”

Segura predicts that in the coming months, “the Republicans will make the wrong move if they try to balance the budget during a recession like the Japanese did in the 1990s.”

Although Republicans have made the repeal of Patient Protection and Affordable Care Act a key plank in their “Pledge to America,” they are unlikely to have the votes needed in either chamber to override a presidential veto of such a measure.

“It will be difficult for Republicans to repeal ‘Obamacare,’” Segura said. “They could try a variety of procedural mechanisms to defund it.”

A key question to emerge from these elections is whether Obama will move more toward the center as Bill Clinton did in 1995-1996 or whether the president and Congress will be unable to cooperate, Hirshman said.

In the first of the changes to come, Rep. John Boehner, Republican of Ohio, is slated to replace Nancy Pelosi, Democrat of California, as speaker of the House.

The following is a synopsis of some key Congressional races:

Wisconsin: Longtime Sen. Russ Feingold lost to Republican Ron Johnson. Feingold was ultimately brought down by independent expenditures that bypassed the McCain-Feingold Act, which regulates the financing of political campaigns.

Florida: Republican tea party activist Marco Rubio won a contentious three-way contest with Gov. Charlie Christ and Democratic nominee Kendrick Meek. Through its unpredictability and the surge of the tea party movement in a swing state, this race has represented in microcosm the forces at work in the 2010 midterm elections.

Colorado: The race between Republican tea party candidate Ken Buck and former Denver School Superintendent Michael Bennet was close on Tuesday. Buck’s unexpected primary win over Lt. Gov. Jane Norton and the cash that flowed into this race from out of state made this an unpredictable race for both parties.

Alaska: Due to the write-in candidacy of incumbent Republican Sen. Lisa Murkowski, the results of this triangular race may not be known for days or more. Although Murkowski was defeated in the Republican primary by tea party candidate Joe Miller, her candidacy may yet prevail in Sarah Palin’s home state.

Nevada: With the highest rate of foreclosures and unemployment in the nation, Nevada had been poised to oust Senate Majority Leader Harry Reid. Despite his record of bringing government projects to his home state, Reid’s position as majority leader has made him the lightning rod for discontent. Nonetheless, Reid retained his seat on Tuesday.