So what is Maryland, arguably one of the most reliable Democratic states in the union - that cast its ballots for Jimmy Carter over Ronald Reagan and Al Gore over George W. Bush - doing electing a Republican governor?

Perhaps it was just an aberration, the standard once-in-a-generation alignment of the political stars that puts a Republican in the Governor's Mansion. It last happened in 1966 when a badly split Democratic Party nominated the conservative George P. Mahoney and the state went for Baltimore County Executive Spiro T. Agnew, considered a moderate Republican.

Or perhaps Robert L. Ehrlich Jr. found a very different body politic hidden beneath the veneer of the two-to-one-margin Democrats hold among registered voters.

"I think it could be both," says Matthew Crenson, a political scientist at the Johns Hopkins University. "It could be that the stars aligned in a particular way this time, starting with Parris Glendening's unpopularity and going through Kathleen Kennedy Townsend's campaign. But it could have a longer-term effect. If Ehrlich plays his cards right, it could be the opportunity to build a competitive Republican Party in the state of Maryland."

Those who say Ehrlich's win is a happenstance point to Democratic triumphs: a two-seat gain for the Democrats in the congressional delegation, solid control of the General Assembly, wins in contested county executive races - including Ehrlich's home, Baltimore County - and the continued domination of most local political offices, even in areas where Ehrlich ran strongly.

"From a broader perspective, it is not surprising that we get one of these results," says state Secretary of State John T. Willis, a student of Maryland political history. "In the past we have always gotten [a Republican governor] every four to six election cycles. My suspicion is that elections will revert to Democratic wins and that we have not seen a change in the basic character of Maryland."

James Gimpel, a political scientist at the University of Maryland, College Park, agrees. "This is a Democratic state, unquestionably. ... Only the right set of circumstances allows a Republican to win until they build more of a constituency themselves."

But an argument can be made for Ehrlich's win marking the beginning of a sea change in Maryland. In this scenario, the near-universal appeal of William Donald Schaefer in the 1986 and 1990 elections, and the polarized electorate that went for Parris N. Glendening in 1994 and 1998, hid the fact that a large number of Marylanders were ready to vote for a moderate Republican.

Thomas F. Schaller, a political scientist at the University of Maryland, Baltimore County, points to the fact that the state's traditional suburban counties that are more likely to vote Republican - Baltimore, Anne Arundel, Harford, Frederick and Howard - now overshadow the Democratic strongholds of Prince George's and Montgomery counties and Baltimore City.

And the two-to-one registration in favor of the Democrats statewide includes many who have long voted Republican. That would be the case of voters in the 2nd Congressional District that sent Ehrlich to Washington in 1994. Democrat C.A. "Dutch" Ruppersberger's win in the 2nd on Tuesday was the first for a Democrat there since 1984 and it happened only after redistricting added Democrats. Pollster Keith Haller says that district is full of "Reagan Democrats." Residents there grew up registering Democratic, in part because the Democratic primaries decided so many races.

One of those was Kendel Ehrlich, the governor-elect's wife. "I don't think I knew of anybody who registered Republican," she said before the election. "And I just didn't really give it a second thought."

Trevor Parry-Giles, a communications professor at the University of Maryland, calls these voters "family Democrats."

"There is a difference between being a registered-Democratic state and a liberal state," he says.

Such habitual Democrats help continue that party's dominance in local races. But that is typical of states undergoing a change from one-party domination. In the South, it took decades for the Republican votes cast in national and statewide elections to reach the local level.

Willis says that will not happen in Maryland because the population is fundamentally different. "This is like the George McGovern race in the 1972 presidential elections," he says, comparing the vote for Ehrlich to Richard M. Nixon's landslide victory over the liberal Democrat. "It is not a race that fits a trend line. It is a pure campaign and candidate failure."

Still, Maryland is changing. Most generally agree that on the state level, for the Democratic Party to remain dominant it has to construct a message that appeals to the suburban voters that put Ehrlich in office.

Frederick County's population grew by about one-third during the 1990s to nearly 200,000. It went heavily for Ehrlich.

The migration to the county has included waves of relatively well-off people from liberal Montgomery County and the District of Columbia fleeing traffic congestion and higher taxes. Among the transplants is Frederick's Democratic mayor, Jennifer Dougherty, who moved from Washington in 1987.

"They're not moving from Mississippi, they're moving from Montgomery and Howard counties and they're interested in quality of life - schools and transportation are of high priority to them," says Democrat Donald DeArmon, a Frederick native who lost Tuesday's 6th District U.S. House race to Republican Roscoe G. Bartlett.

Counties up for grabs

Frederick, along with the other so-called "ex-burb" counties that went strongly for Ehrlich, are ripe for whichever party can arouse their interest, DeArmon says.

"This is a moderate group. They are economic conservatives, but our polling shows they are socially moderate," he says. "We need to help people understand that we [Democrats] are the stewards of Maryland's progressive tradition."

Many say Ehrlich has the opportunity to use his win to put a different face on the state Republican party that will keep those voters in its fold. Once a moderate party of people like Sen. Charles McC. Mathias and Montgomery County Republican Constance A. Morella, it became dominated by ideological conservatives over the past 20 years, a legacy that Ellen R. Sauerbrey could not shake in her runs against Glendening.

During his two terms, Glendening enhanced the state's - and the Democratic Party's - liberal image with an ambitious agenda that not only focused on higher education, environmental protection and curtailing suburban "sprawl," but also included a gay anti-discrimination measure and a significant expansion of the state's minority business set-aside program.

Much of his agenda clearly had popular backing. But Glendening also succeeded, in part, because Maryland's constitution grants the governor broad powers - especially with the budget - which provide leverage in bargaining for pet causes. He also enjoyed a robust economy through most of his terms.

Moderate, on average

Many legislators who worked with Glendening viewed the state as essentially moderate before Ehrlich's election - and they still see it that way.

"Maryland is made up of so many different parts," says state Sen. Christopher Van Hollen Jr., elected Tuesday to Congress from the generally liberal 8th District in suburban Washington. "You've got parts of the state that are more conservative - Baltimore County, the Eastern Shore, western Maryland. When you sort of average it out, it's moderate."

Many think that if Maryland is to become a genuine two-party state, Ehrlich will have to make sure that moderate face stays on the state's Republican Party to permanently convert those who strayed from the Democratic fold to vote for him.

"The best thing Ehrlich can do for the Republican Party is to be a good governor," Gimpel says. "If people see a Republican do a good job as governor, there will be more tendency to consider Republicans in the future for other levels of office. ... People will now see that Republicans turn out not to be as evil as the grandparents and parents said. They may revise their judgments."