ANCHORAGE — Sen. Lisa Murkowski of Alaska conceded late Tuesday in her Republican primary race against Joe Miller, a lawyer from Fairbanks who was backed by tea party activists, Sarah Palin and other conservatives.

Miller, who has proposed drastic cuts in federal spending, had trailed badly in local polls in the weeks before the election but benefited from a last-minute flood of advertisements, mailings and automated calls casting Murkowski as a Democrat in disguise. An abortion-related ballot measure also brought conservatives to the polls.

Many people said Murkowski’s failure to respond to Miller’s attacks had played an important role in her defeat. But she suggested Tuesday that she had no regrets.

“I’m so proud of the campaign that we conducted,” she told reporters at her campaign headquarters here as dozens of friends and family members surrounded her and cheered. “It was honest. It was upright. It was energetic. It was what a campaign in Alaska should be.”