Could Barack Obama be facing a challenger from the Democratic center when he runs for re-election in 2012?

That is one spin we can put on the resignation of Indian Senator Evan Bayh who announced today he is giving up his safe seat.

We know that Bayh was upset that he was not picked as V.P. by Obama after making it into the final three. He had previously made the final cut with John Kerry as well.

Now he will be free and independent of the party and with the Obama poll numbers starting to drop dramatically it is not outside the realm of possibility that he could face a challenge from within his own party for the nomination.

Not since Ted Kennedy ran against Jimmy Carter in 1980 has there been such a challenge to the incumbent. Bayh knows however, that the Obama victory was due to the incredible influx of young voters and impassioned Obama supporters to the process.

They may not be around this time, given the fact that Obama so far has deeply disappointed them. That could leave a route open for Bayh if he decided to try.

By resigning a safe seat he has certainly given himself options. He has $12 million in the bank. Obama is fairly or unfairly seen as too far left by many voters, Bayh is a centrist , a fact shown by his ability to get re-elected in Indiana, usually a bedrock Republican state.

Will he challenge Obama? Too soon to say but I would not rule it out.