Indiana Senator Evan Bayh has $10.3 million on hand in campaign cash…but he isn’t campaigning.

Bayh has declined to seek a third term for the Senate, and while he has donated some of his money to other Democrats, he’s sitting on millions, and it’s unclear what he will do with the money.

Legally, he could use it for a 2012 gubernatorial bid, but he hasn’t yet announced his post-Senate plans.

From Politico:

Bayh has by far the most cash-on-hand of any retiring senator who is not seeking elective office this cycle, intensifying expectations that he is saving the cash for a future statewide or national run.

But Democrats battling to save their Senate majority seem eager to get as much of Bayh’s money as they can right now.

“We have certainly solicited and invited every member to give the maximum that they are able to help the effort,” said New Jersey Sen. Robert Menendez, DSCC chairman, in a recent interview when asked about Bayh’s campaign funds. “And clearly, the greater that we have a participatory caucus, the better position we’ll be in for the successes that we want this coming November.”

In the last quarter, Bayh did cut a $500,000 check to the Indiana Democratic Party – in addition to another $1 million he gave the state party back in March. But those resources are essentially devoted to Hoosier State races all the way down to the local level, rather than to the expansive nationwide field of Democratic candidates running for Congress.

During the last three months, Bayh donated $2,000 to New York Sen. Kirsten Gillibrand and $4,000 to Robin Carnahan, the Missouri Senate Democratic candidate. And in past quarters, he’s given similar-sized sums to at least 10 other Democratic candidates, including Senate Majority Leader Harry Reid (D-Nev.) and Sen. Patty Murray (D-Wash.).

But the lack of transfers of much-bigger amounts – like $2 million that New York Sen. Chuck Schumer gave to the DSCC last quarter and $100,000 given to the committee by retiring North Dakota Sen. Byron Dorgan – only fuels speculation that Bayh may be saving his money for either another run at Indiana governor’s mansion or a future run for national office.