The result was the largest reshuffling of the House of Representatives in 50 years.
For the first time since 1982, when exit polls began measuring support for Congressional candidates, Republicans received a majority of women’s votes. Two years ago, House Democratic candidates won women by 14 points.
Catholics, independents and voters age 60 and older also sided with Republicans by margins not seen since 1982.
Independent voters, a key to President Obama’s election two years ago, turned sharply to the G.O.P. Republicans also won more support than usual from reliably Democratic constituencies: less affluent and less educated voters, urbanites and voters from the nation’s East and West. A notable exception was black voters, who continued to support Democrats in strong numbers.
The generational divide exposed in the 2008 election was more pronounced. Voters under 30 were the only age group to support Democrats but made up just 11 percent of the electorate, typical for a midterm election. By contrast, voters aged 60 and older represented 34 percent of voters, their highest proportion in exit polls since 1982.Experts said that about 42 percent of voters had cast ballots, which is typical for a midterm election.