WASHINGTON (AP) -- Rep. Dan Lungren knows what it's like to have a big bull's eye plastered on his back.
The Democratic Party and labor and environmental groups have spent $4.7 million on TV commercials and other efforts to unseat the nine-term Republican congressman from California. That makes him one of the biggest targets of outside groups, which are throwing unprecedented sums of money into House races this year.
"I don't recognize the person they're portraying," Lungren said about the ads that paint him as an ally of Wall Street and enemy of Medicare and abortion rights. He added, "Yeah, these ads have a considerable impact."
The chance to influence the outcomes of the Nov. 6 election has led the political parties and scores of corporate, union and other organizations to spend a record $253 million so far on their own TV ads, radio spots and other expenses in House races, according to the nonpartisan Center for Responsive Politics, which monitors campaign spending. That compares with $236 million two years ago.
The Supreme Court's Citizens United ruling in 2010 allowed such spending without limits, and sometimes without identifying contributors, but it must be done independently, without consulting candidates.
"We try to play where we can have an impact," said Seth Johnson, who oversees political spending by the American Federation of State, County and Municipal Employees. It has spent $800,000 on ads attacking Lungren, and poured millions more into other races.
Of total spending by groups outside the candidates' own campaigns, $139 million has been for Republicans and $114 million for Democrats. That GOP advantage is expected to swell as well-financed conservative groups such as American Crossroads, organized by political operative Karl Rove, spend more in the final push before the election.
California, with nine competitive House races, has seen the most outside spending, at $36 million, according to the Sunlight Foundation, a nonpartisan group that tracks political spending. Other states where groups have spent into eight figures are Illinois with $30 million, New York with $24 million, Ohio with $14 million and Florida with $10 million.
As of Friday, more than $8 million has been spent by outside groups on each of a pair of races: Republican Keith Rothfus' attempt to oust Democratic Rep. Mark Critz in Pittsburgh's northern suburbs, and a bitter race in northeastern Ohio between two incumbents, Democrat Betty Sutton and Republican Jim Renacci.
Lungren's Democratic opponent is physician Ami Bera. Outside groups, mainly the GOP and the U.S. Chamber of Commerce, have spent $2.7 million against Bera. Total outside spending in this race is $7.4 million so far.
Outside spending has topped $1 million in 57 House races and $3 million in 32 contests, according to the Sunlight Foundation, and that spending has benefited Republicans more in about 60 percent of the contests. In the entire 435-member House, only about 60 races are considered competitive.
Half the outside spending has occurred this month and one-third came in the past 10 days, Sunlight said.
Much of the money is for television. From June 1 through Oct. 21, House candidates and groups helping them aired 195,000 spots on broadcast and national cable TV stations for Democrats and 203,000 for Republicans, according to the Wesleyan Media Project, which analyzes campaign advertising data from a private company, Kantar Media/CMAG.
The area around Sacramento, Calif., where Lungren's district lies, features three other competitive House races involving Democratic Reps. John Garamendi and Jerry McNerney and GOP Rep. Jeff Denham.
TV viewers there have been bombarded with 11,000 political ads in the past three weeks alone plus other spots for statewide ballot propositions, said Michael Franz, a Bowdoin University government professor who helps run the Wesleyan project. An ad by the House GOP campaign arm accuses Bera of favoring tax increases, while one by Democrats hits Lungren for opposing stem cell research.
"You can't turn around without seeing their eyes staring out at you from your TV screen," said Kim Nalder, a political science professor at California State University, Sacramento, who studies campaign advertising.
The biggest spenders are each party's House campaign organizations. As of Friday, the National Republican Congressional Committee was outspending the Democratic Congressional Campaign Committee, $57 million to $46 million.
Other top spenders include the Chamber of Commerce and the anti-tax Americans for Tax Reform on the Republican side, and the Service Employees International Union and AFSCME on behalf of Democrats.
The Chamber of Commerce has spent millions in about 40 congressional races, said Rob Engstrom, the business group's political director.
"What are the races that are going to determine a pro-business majority" in Congress, Engstrom said of how the group decides where to spend.
Besides opening the door for unlimited spending by large organizations, the Citizens United ruling also led to the formation of obscure groups that pump money into House races with voters knowing little about who is behind the money.
The Treasure Coast Jobs Coalition, formed this July, has spent $2.2 million opposing Democrat Patrick Murphy's attempt to unseat GOP Rep. Allen West of Florida. Much of its money comes from casino magnate Sheldon Adelson and New Jersey pharmaceutical executive Richard Roberts. Both often contribute to GOP causes.
Murphy's campaign has been helped by about $170,000 in spending by American Sunrise, a political committee started in January and financed largely by Murphy's father, Thomas.
In a battle for an open House seat in northwestern Connecticut, the Government Integrity Fund is spending $1.1 million on ads attacking Democrat Elizabeth Esty, a former state legislator, saying, "Keep tax and spend politician Elizabeth Esty out of Congress."
The website of the Integrity fund, based in Ohio, says it favors individual freedom and limited government. Federal election reports reveal little about its contributors, and listed officials did not return messages seeking more information about why they entered the Connecticut contest.
Chris Cooper, spokesman for Esty's Republican opponent, Andrew Roraback, complained that Democratic ads unfairly link Roraback to tea party politicians. "If these outside dollars can help tell the truth about Andrew's record, then we feel it will even the playing field," Cooper said.
He noted that Esty has received nearly $1.1 million from the Democratic Congressional Campaign Committee.
Democrats argue there is a difference between the Government Integrity Fund's undisclosed donors and their party's congressional campaign fund, whose donors are reported publicly.
"It has a huge impact," Rep. Steve Israel, D-N.Y., who heads the Democratic committee, said of the Integrity Fund's spending. "It's a hijacking of democracy."
In the northern Chicago suburbs, freshman GOP Rep. Joe Walsh has struggled against his well-financed Democratic opponent, Tammy Duckworth, a wounded Iraq war veteran and a former official with the Department of Veterans Affairs. In recent weeks, the Now or Never PAC, a Missouri-based political action committee, has spent $1.8 million to help Walsh.
The bulk of the group's money has come from the conservative Americans for Limited Government, based in Virginia, which Walsh's congressional website says he helped found.
Walsh spokesman Justin Roth said the lawmaker has had no contact with that group for over a decade and knew nothing of its contribution to Now or Never.
Officials from Limited Government and Now or Never said Walsh had nothing to do with Now or Never's decision to assist him.
A Democratic Party campaign group, the SEIU and the liberal CREDO political committee have assisted Duckworth, though in far smaller amounts.