WASHINGTON (October 27, 2012)—U.S. Rep. Dan Lungren, R-Calif., 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 congressman.

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.

A Supreme Court in 2010 allowed such spending without limits, and sometimes without identifying contributors, but it must be done independently, without consulting candidates.