Republicans will maintain majority in the U.S. House of Representatives, as votes were still being tallied for a number of races.

While the GOP keeps control, a number of moderates on both sides lost, which is likely to make the House even more polarized.

For example, Rep. Larry Kissell, a moderate North Carolina Democrat, lost his bid for reelection, as did Reps. Charlie Bass, R-New Hampshire, and "Bob" Dold Jr., R-Illinois.

Some of the tea party-backed GOP freshmen who had helped their party secure control two years ago were given the heave-ho Tuesday by voters. They include Reps. Joe Walsh and Bobby Shilling of Illinois, Anne Marie Buerkle and Nan Hayworth of New York and Francisco Canseco of Texas.

House Republicans lost in states that President Barack Obama won handily, including four GOP seats in Illinois. At least five Democratic incumbents also lost -- Rep. Ben Chandler of Kentucky; Rep. Larry Kissell of North Carolina, Rep. Leonard Boswell of Iowa, Rep. Kathy Hochul of New York and Rep. Mark Critz of Pennsylvania.

Winners included Rep. John Barrow, a Georgia moderate Democrat; Rep. Jesse Jackson Jr., who has been receiving treatment for a mood disorder; and Joseph Kennedy III of Massachusetts.

"With this vote, the American people have also made clear that there is no mandate for raising tax rates," Speaker John Boehner told supporters at the Ronald Reagan Building in Washington.

He had told CNN on Sunday that the GOP "might" pick up more seats in the House.

"I feel pretty good about at least maintaining the numbers that we have," Boehner said then. "After winning 65 seats from the Democrats in the 2010 cycle, and all the experts been talking about how many seats we're going to lose -- five, 10, 15 -- but I never bought into the idea that we had to lose any seats."

After Obama was declared the winner, Boehner issued a statement that made no mention of taxes, but did focus on the economy. "If there is a mandate, it is a mandate for both parties to find common ground and take steps together to help our economy grow and create jobs, which is critical to solving our debt," he said.

"Americans were unwilling to hand the speaker's gavel back to Nancy Pelosi because her party chose to double down on the same failed policies that caused her to lose it in the first place," said National Republican Congressional Committee Chairman Pete Sessions of Texas, in a statement, referring to the minority leader. "Just as in 2010, our House Republican candidates listened to the American people and rejected the Democrats' tax-and-spend agenda that threatens the American Dream."

Going into the election, Republicans controlled the House by 242-193. Though all 435 members faced voters on Tuesday, control of the chamber rested on some 50 to 60 races that were considered competitive, some of them because of redistricting.

The number of swing districts has shrunk in recent years as GOP legislatures have shored up their seats and Democratic-led state houses have strengthened their party's districts.

Democrats needed to pick up 25 Republican seats to regain control.

Pelosi and other Democrats noted that 58 Republicans represent districts won by Obama in 2008; they pointed to those wins as a template to a successful election night, but by shortly after 9 p.m., CNN projected that they would not achieve their goal.

David Wasserman, who analyzes House races for the Cook Political Report, said Democrats were waging competitive campaigns in just 32 of those districts -- not enough to regain control of the House.

Stuart Rothenberg, an independent campaign analyst, projected last week that Democrats would gain two to eight seats.

The battleground for many of these House races had tilted increasingly toward the Northeast and the Midwest, after a number of moderate Democrats lost in Southern districts in the 2010 midterms.

In Illinois, Democrats saw opportunities to defeat tea party freshman Rep. Joe Walsh, seven-term Rep. Judy Biggert and a moderate Republican freshman, Rep. Bob Dold.

Democrats also set their sights on freshmen Reps. Nan Hayworth, Chris Gibson, Ann Marie Buerkle, and Michael Grimm in New York.

Democratic campaign officials predicted they could upset several GOP incumbents in California.

But California Rep. Xavier Becerra, one of Pelosi's top lieutenants, acknowledged, "We'd need a wind" to get the kind of gains that would put Democrats back in control.

Tea party fades as 2012 factor

Two years after the tea party helped Republicans seize control of the House, it had faded as a factor.

House Republican candidates were still stressing the core issues that the tea party movement pushed in 2010 -- less government and a focus on cutting federal spending and the deficit -- but Republican candidates were "not wearing the tea party label on their sleeves," one senior GOP strategist working on House races said recently.

Democrats, bolstered by polling that shows that many voters blame the tea party for gridlock in Washington, had tried to try to pin the label on virtually every Republican incumbent and challenger.

The "Tea Party Republican Congress has a 13% approval rating," House Democrats' campaign chief Rep. Steve Israel of New York told reporters last month. He said Democrats had a chance to regain the majority because "there is a deep sense of buyer's remorse spreading throughout this country."

With the bulk of this cycle's competitive races concentrated in districts represented by more moderate members of each party, the outcome of this election could mean an even more polarized House in 2013.

The GOP conference could include more conservatives and fewer moderate Democrats, whose ranks were decimated in 2010. That could tilt the Democratic caucus leftward.

A recent study by the Cook Political Report found that the number of swing districts in the nation dropped from 164 to 99 over the past 14 years. That decline has widened the ideological divide between the two parties.

"There's a remarkable reduction in the number of members who have an incentive to compromise," Wasserman told CNN.

Key House race snapshots

Arizona 1: Jonathan Paton (R) vs. Former Rep. Ann Kirkpatrick (D)

Open Republican-held seat

This redrawn district covers most of northern and eastern Arizona. The Democratic nominee was Ann Kirkpatrick, who was elected in 2008 and was swept out in the Republican wave two years later. The Republican nominee was Jonathan Paton, a former state senator. Kirkpatrick had a sizable fundraising advantage over Paton, but national Republicans invested heavily to help close the gap in TV ads. This seat was a top priority for both parties.

Arizona 2: Rep. Ron Barber (D) vs. Martha McSally (R)

Democrat Gabrielle Giffords would have run here had she sought a fourth term. Giffords is recovering after being shot in January 2011 in Arizona. Her district director Ron Barber, who was also wounded, won a special election to fill her seat when she resigned last January. His opponent was Republican Martha McSally, a retired Air Force colonel and combat pilot. Barber had a financial advantage at the start of October though McSally remained competitive on the airwaves. Still, Barber was expected to win.

Arizona 9: Kyrsten Sinema (D) vs. Vernon Parker (R)

New district

The battle for this new district pitted Democrat Kyrsten Sinema, a former state senator, against Republican Vernon Parker, the former mayor of Paradise Valley. Both parties invested heavily in the race, though a Democratic super PAC tipped the TV ad war balance of power slightly in the Democrat's favor.