Freshman Sen. Joe Manchin (D-W.Va.) harshly criticized President Obama’s budget priorities in a Senate speech on Tuesday.

Manchin, the first-term senator who won a competitive special election to fill the late Sen. Robert Byrd’s (D) seat and who must stand for reelection in 2012, accused Obama of having “failed to lead” on budget and spending issues.

{mosads}”We will likely have votes on two proposals today, and both our options are extremely partisan and unrealistic. And neither one will pass,” Manchin said.

“Why are we doing all this when the most powerful person in these negotiations — our president  — has failed to lead this debate or offer a serious proposal for spending and cuts that he would be willing to fight for?” the West Virginia Democrat added.

Manchin’s been careful about crafting a centrist image, mindful of the bruising battle he endured in 2010 and the tough challenge he’s expected to face in 2012.

The former governor of West Virginia, Manchin sprinted toward the right upon securing the Democratic nomination to succeed Byrd, the state’s long-serving voice in the Senate. Manchin, for instance, opened the door to voting with Republicans to repeal healthcare reform, and memorably produced a campaign ad in which he fired a rifle at a copy of the cap-and-trade bill.

Manchin rejected the president’s proposal to fund the government over the remainder of the fiscal year as well as the Republican alternative, both of which are set for a vote Tuesday in the Senate.

Manchin called the votes a bit of “political theater,” and suggested that the differences between the two parties on spending would only be resolved once Obama gets involved in a serious way.

“This debate will be decided when the president leads these tough negotiations. And, right now, that is not happening,” Manchin said. “Respectfully, I am asking President Obama to take this challenge head on and propose a compromise plan for dealing with our nation’s fiscal challenges.”

Republicans pounced on Manchin’s speech. National Republican Senatorial Committee (NRSC) communications director Brian Walsh noted that “this isn’t the first time we’ve seen this type of political posturing from West Virginia’s junior senator.”

Manchin is one of the NRSC’s top targets for 2012.

— This post was updated at 10:56 a.m.