HARRISBURG - Democratic Party enrollment surged past the 4 million mark yesterday, setting a state record on the last day for Pennsylvanians to register to vote in the April 22 presidential primary election.

The figures, which showed modest declines in the ranks of Republicans and independents, reflected intense interest in the race for the Democratic presidential nomination and recruitment efforts by candidates Sens. Hillary Clinton, of New York, and Barack Obama, of Illinois.

Since last year's election, the number of Democrats increased by more than 161,000 - more than 4 percent - to at least 4,044,952. No political party in the state had previously reached the 4 million threshold. Registration in the GOP shrank by about 1 percent to 3,215,478 statewide.

The figures released by state elections officials did not include the final hours of voter registration in the state's 67 counties or mailed-in applications, which will count as long as they are postmarked by yesterday.

The largest percentage gains were concentrated in the Philadelphia suburbs and in central Pennsylvania, mostly in counties where Republicans still outnumber Democrats.

Of the more than 8.2 million Pennsylvania voters, more than 120,000 are people not previously registered.

With four weeks remaining until the primary, Clinton retains a strong lead over Obama in Pennsylvania. A Quinnipiac University poll earlier this month showed Clinton favored by 53 percent of likely Democratic voters, and Obama by 41 percent.

The business of registering Pennsylvanians to vote was brisker than ever in many counties on the last day for registering.

"It's very heavy. We had people at the counter long before we opened up" Monday morning, said Joseph Passarella, director of voter services in Montgomery County.

Montgomery County is among the suburban Philadelphia counties that have seen large increases in Democratic enrollment.

The county office stayed open Saturday to accommodate late registrants. *