Washington -Even before Pennsylvania Sen. Arlen Specter switched to the Democratic side, Republican leaders were warning that their national party was in danger of becoming a regional one.
Specter's departure, part of a larger Republican shift away from the Northeast, has left a hole on the political map. For the first time since the founding of the Republican Party in the 1850s, there is not a single Republican senator from Maryland or any of the four states that border it.
That development puts new emphasis on a question confronting Maryland Republicans: If the Republican Party is becoming a regional party, is Maryland part of that territory?
The answer appears to be: Yes, but just barely.
This year, for the first time in decades, Maryland is left with only a single Republican congressman in Washington. And with a national debate stirring about how to reinvigorate the party, there are few signs that Republicans in the state have developed a plan for turning things around.
Senate Minority Leader Mitch McConnell of Kentucky, the top elected Republican in the country, said earlier this year that his party "seems to be slipping into a position of being more of a regional party than a national one."
Specter's switch and the recent failure to pick up a historically Republican House seat in a special election in upstate New York are the latest examples of a trend that has obliterated Republican representation in the mid-Atlantic and up the East Coast.
At a news conference announcing his decision to rejoin the Democratic Party, the veteran senator pointed to a pivotal Maryland contest last year when asked whether he felt that Republicans had pushed him out.
"Republicans didn't rally to Wayne Gilchrest in Maryland. He was beaten by the Club for Growth and the far right," Specter replied. "They lost the general election."
With the loss of Gilchrest's seat, the state's lone Republican at the national level is 82-year-old Rep. Roscoe Bartlett of Frederick.
The defeat of moderates like Gilchrest, often in party primaries, has contributed to the dwindling number of northern Republicans in Congress. In the 10 states from Maryland through New England, just 10 Republicans remain out of a total of 73 House seats.
Gilchrest, in an interview, said he had given consideration to switching parties but decided that it wouldn't have been worth the effort unless he planned to remain in office for another decade.
"I knew that I wasn't going to be around that much longer anyway," said Gilchrest, praising Specter for putting the "integrity the country needs for good public policy" above "loyalty or disloyalty to political mythology."
The sharp drop in the percentage of voters who called themselves Republicans in the presidential election has extended into this year, according to a new Pew Research Center analysis of public opinion polls. During the past five years, according to Pew, the party has lost a quarter of its base.
In Maryland, too, Republicans have been in decline since 2002, when Robert L. Ehrlich Jr. became the first Republican since Spiro Agnew to be elected governor.
According to state Board of Elections figures, the number of registered Republicans had fallen to 26.9 percent, compared with 56.8 percent for the Democrats, by the start of this year. the past seven years, the number of Democratic voters in the state has expanded more than two-and-a-half times faster than the Republicans.
"We're one of the most Democratic states in the entire country," said John Willis of the University of Baltimore, former secretary of state and co-author of a forthcoming book, Maryland Politics and Government.
That Democratic tilt is particularly evident in presidential elections. Maryland was President Barack Obama's sixth-best state last year.
But Willis cautioned that Maryland's extreme political polarization makes it hazardous to generalize. In western Maryland, for example, Garrett County hasn't voted for a Democratic presidential candidate since its formation in 1872.
"Maryland is Republican in Western Maryland and in many places on the [Eastern] Shore, although the Shore is fairly competitive at the local level," he said.
Republicans also hold a fairly stable portion of seats in the state legislature - about 30 percent. And they remain competitive at the local level in many areas - though not Montgomery and Prince George's counties or the city of Baltimore, which have no Republican officeholders, Willis noted.
Privately, Maryland Democrats are already talking about whether they can redraw district lines after next year's census in ways that would give them a chance to capture all of the state's congressional seats. States that currently have no Republicans serving in the House of Representatives include Massachusetts, Connecticut, Rhode Island, Maine, New Hampshire and Vermont.
Maryland Republicans, meantime, say they hope to rebound in next year's election for governor, the General Assembly and House of Representatives.