Still, senior Merkel ally Horst Seehofer, the conservative governor of Bavaria, conceded that the government needed to do a better job of explaining its policies. He told ZDF television he had noticed a "communication deficit" on the campaign trail.
There was shocked silence at the Free Democrats' election event as exit polls showed the party slumping below 5 percent of the vote.
Four years ago, the party won nearly 15 percent, its best-ever result; over the past week, it had pleaded for support from Merkel supporters to keep it afloat. Merkel frequently called the outgoing coalition "the most successful government since reunification" 23 years ago, but her own popularity didn't extend to the coalition.
"It's the bitterest, saddest hour of the Free Democratic Party," the party's leader, Vice Chancellor Philipp Roesler, said.
Gabriel, the political scientist, said conservative voters who voted for the Free Democrats in 2009 "returned in droves" to Merkel. The smaller party, which was long the kingmaker of German politics, "isn't considered competent by the voters anymore," he said.
The conservative result was close to an absolute majority because of the rule requiring parties to win 5 percent support to claim seats in the lower house. Many small parties miss that threshold, meaning their votes don't count in the division of seats.
Sunday's result gives the conservative bloc of Merkel's Christian Democratic Union and its Bavaria-only sister, the Christian Social Union, 311 seats in Parliament. The Social Democrats won 192 seats, the Greens 63 and the Left Party 64.
Turnout edged up to 71.5 percent from 70.8 percent four years ago.
Associated Press correspondents Frank Jordans, Kirsten Grieshaber, Robert H. Reid and David Rising contributed to this report.