A conservative Maryland state Senator is taking steps to challenge Rep. Wayne Gilchrest in the 2008 Republican primary, though he said Friday that he has not completely decided whether to make the race.

State Sen. Andrew Harris said he has thought about challenging the Congressman for several months and was leaning against it until two weeks ago, when Gilchrest joined 16 other House Republicans in voting for a resolution that criticized President Bush’s proposal to send 21,500 additional troops to Iraq.

“That has changed the calculus a little bit,” Harris said.

Gilchrest easily turned back conservative challengers in 2002 and 2004, but Harris, the sole physician in the state Senate, could be more formidable because he is no stranger to tough races.

He was elected to the state Senate in 1998 by ousting the sitting Minority Leader, a moderate, in the GOP primary. Last fall, he beat back an expensive general election challenge in his Baltimore County district from the president of the Maryland State Teachers Association, whose campaign was fueled by labor support.

Harris also has collected chits throughout the 1st district, which spans both sides of the Chesapeake Bay, by campaigning for Republican candidates for legislative and local offices in 2006.

But Harris conceded that Gilchrest remains a difficult target. Even though conservative groups routinely criticize him, the unassuming former teacher and house painter remains a popular figure in his district.

Although he is not a prodigious fundraiser, Gilchrest began 2007 with $308,000 in his campaign account, after spending just $178,000 on his 2006 re-election, which he won with 69 percent of the vote. Harris, who would not have to sacrifice his Senate seat to run for Congress, said he spent about $250,000 on his own re-election last year and estimated that he would need $750,000 to beat Gilchrest.

Both Gilchrest’s chief of staff and communications director could not be reached for comment by press time Friday. But Chris Baron, a spokesman for the Republican Main Street Partnership, a national group that aids GOP centrists, said Gilchrest’s reputation as “an independent fighter” with a strong record on taxes, the environment and agriculture should serve him well in a primary with Harris.

“He’s somebody who we think is a good fit for his district,” Baron said.

Still, Harris said he detected a restlessness among Republican voters in Maryland that could accrue to his benefit, especially since the Iraq vote. He called Gilchrest wrong on economic policies, social issues and the Iraq War, and said Republicans want a more faithful conservative in a district that gave Bush 62 percent of the vote in 2004.

“I just don’t understand how Congressman Gilchrest didn’t get the message from the last election that Republicans are supposed to return to their base,” Harris said. “A district as Republican as the 1st Congressional district should elect as conservative a Republican as we can.”

Harris said he would spend the next several weeks meeting with interest groups and attending local Republican meetings before deciding whether to run. He could be aided by several national organizations, including the Victory Caucus, a new group put together by conservative talk show hosts dedicated to defeating the 17 House Republicans who opposed the troop surge, and the Club for Growth, the anti-tax group.

Last year, Gilchrest was listed as 212th of 232 Republican House Members when it came to supporting club priorities, and the group’s political action committee has worked against Gilchrest in the past.

In 2002, the club endorsed David Fischer, a lawyer and political neophyte who took just 36 percent of the vote in his primary challenge against Gilchrest. Later that year, the club sent Gilchrest a check for the general election — which he refused to deposit and has kept as a souvenir.

Two years later, the club stayed out when another conservative state Senator, Richard Colburn (R), took just 38 percent of the primary vote against Gilchrest.

Club President Pat Toomey, a former Pennsylvania Congressman, said the group is aware of Harris but has not yet had a conversation with him.

“We’ll just have to see how it develops,” Toomey said.