Anchorage Mayor Mark Begich (D) moved one step closer to taking on Sen. Ted Stevens (R) Wednesday by announcing he was forming an exploratory committee to run for the Alaska political legend’s Senate seat.

“Alaskans across our state have been urging me for months to run for the Senate,” Begich said in a conference call with reporters. “Forming this exploratory committee allows me to solicit the views of Alaskans under the federal elections process.”

National Democratic leaders have been wooing Begich for months to take on Stevens, who is viewed as at his most vulnerable in decades because he currently is under federal investigation.

Begich announced his exploratory committee from his home in Anchorage, saying the filing marks the beginning of a massive listening tour across the expansive state. Begich said he would make a decision before Alaska’s June 2 filing deadline.

Even though Begich stopped short of announcing an official campaign, at least one Alaskan Democratic operative thinks he eventually will get in. According to that operative, Begich likely is waiting for the Anchorage municipal elections on April 1.

“He’s gearing up so he can raise money, so when he jumps in the race in April, he’ll have the cash on hand,” the operative said.

The operative said another possibility is that Begich is waiting to see if there is any more movement in the Stevens investigation before the filing deadline, so he could build off the momentum of what could be more bad news for the incumbent.

“We keep hearing rumors about imminent indictments,” the operative said. “Perhaps there’s some calculus about wanting to be engaged before the indictments occur.”

Republicans have dominated state politics for decades, but Democrats believe some of Stevens’ legal and political woes give them a shot at taking the seat, particularly with a marquee candidate like Begich as their nominee. Stevens, whose campaign spokesman did not respond to a request for comment Wednesday, is facing perhaps his most challenging re-election bid after serving in the Senate for 40 years.

The 84-year-old Republican is part of a a wide-ranging corruption probe led by the Justice Department — which has identified ties between an Alaskan oil services company, VECO, and prominent GOP politicians — including whether the company illegally remodeled Stevens’ home. The FBI raided his house late last summer as part of the investigation.

Stevens maintains he is innocent and paid all of the bills that VECO presented to him.

National Republican Senatorial Committee spokeswoman Rebecca Fisher said her committee believes Stevens will be returned to Washington, D.C., this November.

“I wouldn’t say he’s having his most challenging race since he took his seat — but as a habit we’ve told all our candidates to take this election cycle very seriously and I believe Sen. Stevens is doing that,” Fisher said.

Despite his current legal woes, Stevens’ fundraising has not slowed down significantly. He raised more than $1.5 million in 2007 and boasted more than $1 million in cash on hand as of Dec. 31.

Stevens already has a primary challenger in wealthy businessman David Cuddy (R), who first took on the Senator in a heavily self- financed bid in 1996. Former state Rep. Ray Metcalfe, a gadfly who has helped expose some of the corruption in the state, has filed for the Democratic primary, but national Democrats have made no secret of the fact that they have been courting Begich since early last year.

“We’re pleased with his announcement today and should he ultimately decide he is running, we think he’ll be a great candidate who can win the race,” said Democratic Senatorial Campaign Committee spokesman Matt Miller.

Most recently, Senate Majority Leader Harry Reid (D-Nev.) met with Begich while he was in Washington. In his announcement, however, Begich said his family was the primary factor in his decision.

“I will say that Sen. Reid has called me in the last week, but that’s not what put me over the top,” he said. “The initial decision for me was how does it work for my family. How does it work for me, my wife, my young son. … We feel that we can manage the change, we can manage the lifestyle change that would occur here.”

Begich is the son of former Rep. Nick Begich (D), who disappeared while on a campaign flight in 1972 and was presumed dead.

Begich’s second and final term in the mayor’s office ends in 2009. If elected, the 45-year-old Democrat also would be one of the youngest members of the Senate.