If there was ever any doubt where Alexander X. Mooney stands, consider his surroundings: There is a National Rifle Association rug outside his door, a picture of him with Edwin Meese on the wall and a crucifix hanging behind his desk.

And if there was ever any question about his resolve, there is the poster of Winston Churchill with one of the prime minister's most famous quotations, which the 29-year-old Maryland state senator reads with relish: "Never, never, never, never. Never yield in any way, great or small."

He smiles. "That's how I feel this week."

Tonight, when the Senate begins debate on a proposal to prevent discrimination against gay men, lesbians and bisexuals based on their sexual orientation, the Republican from Frederick County will be leading the fight against it, angered at the notion of providing special rights for what he calls a chosen lifestyle.

It is a familiar role for the youngest member of the Senate, who sits in the back row in the far right corner of the ornate chamber. Though only in his first term, Mooney has been a leading opponent of much of Gov. Parris N. Glendening's agenda over the past three years.

He is fighting the gay rights proposal this year. Last year, he got into a shouting match with the Senate president during debate on the governor's gun safety bill. He has fought efforts by Glendening (D) to limit suburban sprawl, saying new state regulations tread on local governments.

Now in his third General Assembly session, Mooney has carved out a niche as one of the most constant, and sometimes combative, conservative voices in Annapolis. He has tried to stop state funding of abortions, tried to lower taxes and been a constant advocate of smaller government.

As he girds himself for a long fight over the gay rights proposal, Mooney insists he isn't relishing the battle. "I'm really not looking forward to that floor debate. But it's my duty," he said in an interview. "Most of what I do is to stop really bad legislation from passing, to stop the extremely liberal agenda of the governor."

During committee debate on the gay rights bill, Mooney noted that Glendening's brother, who was gay, died of an AIDS-related illness. "If you're not practicing a certain homosexual lifestyle, you're not going to contract that disease," he said. "We're promoting an activity that can result in death."

In a General Assembly dominated by Democrats, there are two kinds of Republicans: those who try to get along with the Democratic leadership in the hope of having some influence, and those who fight Democratic proposals in an effort to carve out a distinct Republican philosophy. Mooney unabashedly fits in the second category.

"I think things down here are so off base that it's hard for a person like me not to object continually," he said.

His mother came to the United States from Cuba, fleeing after the failed Bay of Pigs coup attempt in 1961. His father was from New York. They met while in graduate school at Catholic University but have since divorced.

Mooney is the second oldest of four children whose parents instilled in them a commitment to education and achievement. Two of his siblings went to Yale University. Mooney graduated from Dartmouth College in 1993.

After working on Capitol Hill for Rep. Roscoe G. Bartlett (R-Md.) and as a legislative analyst for the House Republican Conference, he joined a conservative think tank. He quit in 1998 to spend 10 months campaigning full time for a seat in the state Senate. He was not his family's first politician; his mother's brother is Xavier Suarez, the former mayor of Miami.

Mooney scored a surprise victory in the GOP primary. He defeated a four-term moderate Republican in a Frederick County district that has been growing steadily conservative. Other than some part-time public relations consulting, Mooney is a full-time lawmaker.

His assignment to the Judicial Proceedings Committee put him on a collision course with much of Glendening's agenda: It was that committee that bottled up gay rights legislation two years ago.

Glendening has accused Mooney of taking "hysterical positions for fundraising purposes."

Mooney has turned the controversy that his positions generate to his advantage. He has been a constant fundraiser since his election, developing the largest campaign fund of any Republican senator. He has raised more than $150,000, more than six times what the Senate minority leader, Martin G. Madden of Howard County, has collected, records show.

He taps a statewide network, saying that conservatives in liberal areas will send him money to keep his voice in the legislature. His appeals to them emphasize an uphill struggle in a liberal state.

"Parris Glendening and the radical left sneer at conservatives like you and me who object to their outrageous behavior," he wrote in a six-page fundraising letter in August. "I'm not afraid to swim against their liberal tide."

Such talk is helping Mooney emerge as a prominent Republican voice at a time when the party leadership is trying to appeal to more moderate voters. In a state as liberal as Maryland, the GOP has had difficulty electing candidates to statewide offices and, in fact, saw its numbers in the legislature and at the county level shrink after the 1998 election.

But many in the party hear the growing conservative voice from Republicans like Mooney and are beginning to question the future of the party. Within the past two years, two Republican senators have abandoned the party to become Democrats. While not singling out Mooney, they both said they felt uncomfortable with the GOP's increasing conservatism.

Madden said the GOP is large enough to accommodate such moderates as Rep. Constance A. Morella, from a liberal Montgomery County district, as well as Mooney. "Alex fits under the diverse Republican umbrella," he said.

Madden and others see the young senator playing an important role in expanding the party and are especially hopeful he can help reach out to Hispanics.

"Alex is a leader of the effort to help define the party statewide -- a party that badly needs definition -- as a party of lower taxes, smaller but effective government, and strong moral values," said Kevin Igoe, a GOP consultant who works for Mooney but also represents moderate Republican candidates.

Even Democrats offer Mooney praise for his intellect and convictions. Senate Judicial Proceedings Committee Chairman Walter M. Baker, a conservative Democrat from Cecil County, said Mooney has a bright future.

"He's nobody's dummy. He votes his conscience," Baker said. "He does these things because he thinks he's right, and that's all you can ask of a legislator."

Baker has played mentor to Mooney and has even appeared at a fundraiser for the Republican.

But, it seems, Mooney can't give up the fight, even with his friends. Last week, Baker cut off committee debate on the gay rights bill, after allowing opponents to talk several hours over two days, and provided the one vote needed for the bill to advance. Mooney is still smarting.

"I used to look up to Baker until last week," he said. "In my opinion, he caved right in on this one, and I've lost respect for him."

Sen. Alexander X. Mooney plans to vocally oppose the gay rights bill.