St. Mary's County swung further to the right Tuesday, another sign of change in a region evolving from its rural roots and once solidly Democratic base.

"There's a whole lot of Democrats that switched to Republican this year," Carol Oliver, 56, an insurance agent from Charlotte Hall, said at the polls Tuesday. She said all six of her co-workers are Democrats, and five of them, like her, had said they planned to vote for President Bush.

It was still easy for longtime Democratic congressman Steny H. Hoyer to win St. Mary's County in his reelection victory in the 5th District. And registered Democrats still outnumber Republicans in St. Mary's. But the gap is narrowing.

"In the past it was 2 to 1 almost," Democrat to Republican, said Catherine Countiss, the county's supervisor of elections.

Bush won St. Mary's more easily this year than he did in 2000. Four years ago he collected 57 percent of the vote; on Tuesday Bush raised his majority to 63 percent.

And state Sen. E.J. Pipkin, the Republican candidate for U.S. Senate, nearly caught Democratic Sen. Barbara A. Mikulski: 48 percent of the vote for the challenger to 50 percent for the incumbent.

The shift indicates, in part, the increasing presence of the military in St. Mary's. The Patuxent River Naval Air Station keeps bringing jobs, people and money.

Frank Taylor, the chairman of the Democratic Central Committee for St. Mary's, said many of the people moving to the county for the Navy base are Republicans. And he sees another change, among core Democratic voters who are conservative.

"Some folks that are longtime Democrat supporters have shifted their voting preference," he said. "They might still be registered Democrats, but their voting preference has shifted to more conservative candidates," who are more likely to be Republicans in recent years.

Some observers say it is evidence of a larger political trend and point to the election of Republican Robert L. Ehrlich Jr. as governor in 2002. Last year Calvert County partisans saw the scale tip: For the first time, more Republicans registered there than Democrats.

Deborah Martinez, a spokeswoman for the Maryland Republican Party, said that before 2002 just a handful of counties had more Republicans than Democrats. "We've gone from four to eight. And we're hoping with counties like St. Mary's and Harford, within the next couple of years we'll have 10."

Several people, including registered Democrats, said they voted for Bush over his Democratic opponent, Sen. John F. Kerry of Massachusetts, because they liked the incumbent's decisiveness and said he could better protect the country against terrorism.

"I don't like everything that's going on in Iraq, but there's no choice," Oliver said. "Kerry scares me to death, he's so wishy-washy."

Mike Leishear, 29, of Leonardtown, an officer with the Department of Natural Resources Police, said from the polls Tuesday it is easy to see that the county has changed. "I definitely see it leaning more toward the Republican side or moderate Democrats. . . . With so many [defense] contractors moving here and the white-collar corporate jobs, it's no longer the farmers and hard-core Democrats with such a presence."

For details on voter turnout statewide in Tuesday's election, see today's Metro section.

Kirk Larman and Diane Griffin-Pluebell appeal to voters at the North Beach volunteer fire station.