Another section has toppled in the once-solid Republican wall of suburban counties surrounding Philadelphia. Bucks County has joined Montgomery County in going Democratic.

For the first time in 30 years, more voters are registered as Democrats in Bucks as Republicans.

As of Sunday, 185,413 of Bucks County's 427,962 registered voters were on the rolls as Democrats, compared with 181,941 for the GOP, according to figures released by the state yesterday. The remainder - about 14 percent of the total - are registered either nonpartisan or with other parties.

Statistically, the Democrats' advantage in Bucks is minuscule, a fraction of a percent.

But psychologically, it could be huge. Not since 1978 have Bucks Democrats held a lead of any size.

That dominance peaked in 1996, when Republicans built a 48,000-voter advantage, but has been eroding each year since.

"I think 3,000 voters is huge, given where we have been," said Democratic County Commissioner Diane Marseglia. "The bells have been going off in my head all day."

Andrew Warren, a former Republican county commissioner who switched parties in 2005, said it remained to be seen how many are simply Republicans or nonpartisans who wanted a voice in the unusually important April 22 Democratic presidential primary. He said he suspects some of the gains will fall away.

"I don't think we'll see too many Republicans jumping off the Burlington-Bristol Bridge," Warren said of the registration shift. "But it is a feather in the Democrats' hat, and tonight they can dance."

The news comes on the heels of figures showing that in Montgomery County, where Republicans once held a 2-1 advantage, Democrats now hold the upper hand. The state's latest figures show Democrats with an 8,000-voter registration lead.

The GOP retains solid leads in Chester and Delaware Counties.

In Bucks, the number of registered voters has now surpassed the record of 424,888 set in 2004, the last presidential election year. More than 11,000 new county voters have registered since October.

Statewide, registration stands at more than 8.3 million - fewer than 50,000 behind the record set in 2004. Democrats have marked an 8 percent increase since fall, and now have one million more registered voters than do the Republicans.

Such figures are "the most concrete indicator of the interest and intent to participate on April 22," said Rebecca Halton, deputy press secretary for the Pennsylvania Department of State, which includes the elections board. "It is a very exciting election year, and we are seeing some record-setting numbers."

Whether it is a harbinger of local electoral control is another matter. While Bucks and Montgomery have gone Democratic in recent national elections, county-level offices are still dominated by Republicans.

"One has to wonder how much of it is long-lasting," Warren said of the Democrats' registration surge. "I don't know if you could say it was as much a race between the two parties for registrations as it was an intra-squad match between Democrats for Obama or Clinton."

Conservative radio hosts, among others, have urged Republicans to switch parties and vote for Hillary Rodham Clinton in the remaining primaries, hoping to preserve the Democratic infighting for as long as possible.

"Bucks County is privileged to have people of superior intelligence, and they don't listen to Rush Limbaugh," Marseglia retorted. She said that if newly registered Democrats "feel they have a voice in this election, they will stick around."