Sen. Dick Lugar (R-Ind.) raised just under $1 million for his re-election campaign in the first three months of this year, according to preliminary fundraising totals obtained by Roll Call.

Lugar has more than $3 million in his bank account as he embarks on what could be the most difficult re-election campaign of his career.

Lugar is facing a tough challenge from state Treasurer Richard Mourdock, who boasts support from national tea party activists and has criticized Lugar for not being conservative enough.

Mourdock’s campaign has generated a great deal of attention from Indiana Republicans since he announced his bid earlier this year, but the GOP challenger has told reporters that he has raised $125,000 so far for his bid — making Lugar’s fundraising advantage even more important. The six-term Republican will need to rely heavily on his cash reserves to fend off a challenge from his right next year.

Lugar will report that he raised $974,000 in the first quarter of this year.

At least two other candidates are still mulling bids for the Senate. Another Republican, state Sen. Mike Delph, told Roll Call last week that he will make a decision in the coming weeks as to whether he will jump into the race.

Rep. Joe Donnelly (D-Ind.) is also considering jumping into the race. Republicans control the redistricting process in Indiana, and Donnelly’s district is expected to change drastically this cycle — and not in his favor — making the Senate race an enticing option for the three-term Democrat.

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