Sen. Richard Lugar (R-Ind.) is sitting on a warchest of $2.3 million and he says it's growing by the week ahead of what's expected to be a tough primary challenge from the right in 2012.  

Lugar has already held a handful of fundraisers in the new year, including one last week that netted him close to $400,000 for his reelection bid. 

"We had another fundraiser yesterday morning," Lugar told Ballot Box Wednesday. "I'm having fundraisers, not every day, but I would just say this is a good deal more preparation than any other candidate in Indiana has made." 

On Wednesday, Politico reported that Indiana Republicans expect state Treasurer Richard Mourdock (R) to announce a Lugar challenge as early as this month, something Lugar said doesn't come as any surprise to him.   

"It's why we've already started to raise money," he said. "I take seriously any primary competition or general election competition."  

The Indiana Republican, who has sparred with Tea Party activists in recent weeks, said he's ready for the Tea Party-backed challenge and is kicking his fundraising into high gear just as Tea Party groups in the state ramp up their efforts to defeat him. 

Activists in Indiana are still working toward coalescing around a single conservative alternative to the longtime senator. 

"I'm sure there are some groups that will do their own thing, but a majority have agreed that there has to be just one candidate [against Lugar]," said Indiana Tea Party activist Monica Boyer. 

Boyer met with Lugar in December and came away determined to help oust him in a primary.  

"He basically told us how it was," Boyer said of the meeting with Lugar. "There was no discussion and he didn't hear us. From that time on, it was game on." 

A Republican source said a consensus appears to have formed around Mourdock as the candidate of choice among the grassroots and that activists now fully expect him to get in the race sooner rather than later.  

"We have the enthusiasm and the boots on the ground, so we're not intimidated by his money," Boyer said of Lugar's war chest. 

Mourdock and Indiana state Sen. Mike Delph are the two Republicans who top the list of potential Lugar primary challengers. 

Delph is still weighing a bid, but said in an e-mail Wednesday that he remains focused on his current duties as state senator and has no intention of making a decision any time soon. 

"We have more than a full plate here in Indiana," said Delph. "Other pursuits will have to wait until we adjourn."