Conservative Republican Del. Robert Marshall became an official candidate for the 2012 U.S. senatorial race in Virginia this week, challenging Republican and former governor George Allen for the GOP nomination.

Along with frontrunner Allen, Marshall's bid joins tea party leader Jamie Radtke, E.W. Jackson, and David W. McCormick in the June primary. Former Governor Tim Kaine is the overwhelming favorite to win the Democratic nomination.

It is not Marshall's first crack at the U.S. Senate. In 2008 Marshall narrowly lost the GOP nomination to former Gov. Jim Gilmore, who later lost to Democrat Mark Warner. Marshall is also one of the most conservative members of the General Assembly, and is the chief patron of the "personhood bill."

Marshall said that he decided to join the race at this time because he was assigned to a new district, the 13th, and wanted to represent those constituents to the best of his ability. Marshall observed two things when he was going from door-to-door in the new district during the last election. "People asked me if I would run for U.S. Senate," he said, "and they wanted to know if I could beat Tim Kaine."

With the GOP Senate primary coming up on June 5, Marshall's campaign faces competition from Allen and Kaine on both sides.

Marshall has already faced policy battles with Kaine and come out the victor.

In 2006, Marshall's one-man/one-woman Marriage Amendment to the Virginia Constitution defeated opposition from then-Gov. Kaine and was ratified with 57 percent of the ballots in the general election. Marshall also won a lawsuit with a unanimous vote 7-0 to strip unelected transportation authorities of the power to impose taxes. His lawsuit victory blocked 14 taxes in northern Virginia and Tidewater imposed by Kaine.

"I've had experience in clashing with Tim Kaine when he's on the short-end of the stick," Marshall said.

Kaine is not Marshall's only competition. At the start of the New Year, frontrunner George Allen had already raised $2 million to support his campaign. He raised $1 million the final three months of 2011.

Marshall said that he plans on raising enough money for mailing and cable television ads, but he also has to pay attention to what is going on in Virginia legislation.

"I'm not abandoning these statutes," he said, including the issue of Virginia's loyalty oath. His opposition to the loyalty oath, along with others', caused it to be removed from the ballot in a last-minute request from the state Republican Party.

Marshall said that his campaign strategy is to work to get the vote, to get the plurality. "A quarterback does not reveal his strategy to the opposing team," he said.

Although Marshall has a significant group of devoted supporters, most observers are skeptical that he can round up enough tea partiers and social conservatives, peeling them off from the campaigns of Radtke and Jackson, to knock off Allen. Dr. Charles W. Dunn, professor of government at Regent University, says Marshall's strategy is a moot point. "No one thinks he has a chance of winning other than Bob Marshall," he said.

Allen, Dunn said, is a known commodity and has a broad base of support in the Republican Party. "He has the organization and the money," he said. "Republicans are going to want to go with the one they think will win. Why nominate someone who doesn't stand a chance of winning?"

Dunn is not the only who thinks that Marshall will have a tough time competing against Allen. Longtime GOP strategist and former Allen adviser Christopher J. LaCivita said that Marshall's entry into the race is less likely to affect Allen than others.

"There is a finite group of the electorate in this primary that you could call the anti-Allen vote," LaCivita said. "Someone else getting in the race cuts up what was already a fairly small pie into smaller pieces."

Though some question his ability to defeat frontrunner Allen, Marshall said in a statement released from his office on Monday, "I already have a 'can do' record of challenging Tim Kaine and winning in the public arena on major economic and social issues, and I can do it again."

The Associated Press contributed to this report.