Maryland Gov. Martin O’Malley may have his campaign cue cards close at hand for a possible 2010 rematch with Republican Robert L. Ehrlich Jr., whom he unseated in 2006. But those talking points might not prove necessary this time around.

The 51-year-old Ehrlich has been quiet about his 2010 plans. He hasn’t publicly ruled out a comeback try. But he has to weigh the odds of taking on O’Malley, as the Democratic incumbent, in one of the nation’s most Democratic-dominated states.

Ehrlich is expected to make a decision in the latter part of this year, said Paul Schurick, the former communications director during Ehrlich’s administration and a current communications consultant for Womble Carlyle, the firm for which Ehrlich practices law.

“He’s got the luxury of time,” Schurick said, adding that Ehrlich is probably the only serious potential Republican challenger to O’Malley. Schurick described the political environment in Maryland as “unsettled,” and said that voter frustration with taxes and the expansion of government could make Ehrlich a competitive candidate.

O’Malley, though, has already amassed $2 million for his campaign treasury. The former Baltimore mayor hit some rough patches during his first two years as governor, especially after pressing for a tax increase to address a state budget shortfall, but polls have shown more Marylanders approve than disapprove of his job performance.

Ehrlich certainly has plenty of experience at winning elections. He was just 28 years old in 1986 when he won a state House seat. He held that seat through 1994, when he was elected to the first of four terms representing Maryland’s 2nd District, a suburban Baltimore constituency, in Congress. His 2002 win in the open-seat race for governor broke an eight-election Democratic winning streak for that office that dated back to 1972.

Ehrlich’s continued status as the star among Maryland Republicans, despite his failed 2006 bid for re-election, is in part by default. The GOP has a very short list of well-known potential candidates in a state where Democrats hold all statewide elected offices, including both U.S. Senate seats; seven of the eight U.S. House seats; and nearly three-quarters of the seats in the state legislature. Barack Obama ’s easy 2008 win over Republican John McCain , with 62 percent of the vote, marked the fifth consecutive election in which the Democrats carried Maryland for president.

The only Republican whose prominence might compare to that of Ehrlich is Michael Steele, who served as lieutenant governor under Ehrlich and ran a vigorous though unsuccessful bid in the 2006 open-seat U.S. Senate race won by Democrat Benjamin L. Cardin . But Steele’s election in January as chairman of the Republican National Committee makes it unlikely that he will be running for public office again anytime soon.

Lee Cowen, a top advisor on Ehrlich’s 2002 campaign, said he wouldn’t write off the possibility that Ehrlich would run against O’Malley next year. Cowen, managing director at the public affairs firm Dutko World Wide, added that Ehrlich might actually be better positioned than he was in 2006, an election year in which the plummeting popularity of President George W. Bush spurred a national anti-Republican trend.

“In 2006 I think a significant part of why O’Malley was able to beat Ehrlich was voters’ discontent with the Bush administration. In 2010, that will be a distant memory,” Cowen said.

But Cowen acknowledged the shallow pool of potential Republican candidates, stating, “If it’s not Bob Ehrlich, then I don’t know who the GOP goes to next.”

That appears more likely than not to be the situation in which the Republicans will find themselves. Thomas F. Schaller, a political science professor at University of Maryland at Baltimore County, said Ehrlich, after pondering the 2010 race, will likely decide not to run, and the state Republican Party would then turn to a fresh face.

“I suspect it will be someone who’s never run before,” said Schaller, who regularly writes columns for the Baltimore Sun.