MISSOULA, Mont. -

NBC Montana dug into U.S. Sen. Max Baucus' campaign fundraising reports.

Baucus announced Tuesday that he will not run for re-election.

That decision leaves him with more than $4.8 million in the bank and no campaign to spend it on.  Campaign rules won’t let him raise any more money, although he bankrolled more than $1.5 million in the three-month period ending March 31.

Officials say he can use that cash for a number of things, from winding down his office to unlimited transfers to party committees to creating his own political-action committee.

Baucus state director John Lewis says Baucus will look for ways to support the Montana Democratic Party, Democratic candidates and causes.

Since Baucus announced his decision, analysts and others started speculating why he was done with public office.

During an interview today, he said he made the decision based purely on personal reasons.  Baucus said, “I kind of wanted to do something different when I finish this term.  If I ran again, that would mean I'd be about 80 years old by the end of that term.  That really limits one's opportunity to do something else.”

Baucus went on to tell us the Senate has been the best job in the world, but that he wants to return to Montana. You can watch our full interview with Sen. Max Baucus. The video is posted above.