Sen. Russ Feingold has been predicting for some time that Republican John McCain will be the next president.

Feingold now thinks Democrat Barack Obama has a decent chance of beating McCain but says it won't be easy.

The Wisconsin Democrat is a longtime friend of McCain, and the two worked together on the landmark McCain-Feingold campaign finance reform law.

Feingold says people are excited about Obama's candidacy and the climate has become more favorable for a Democratic win than it was. But he says he's not convinced his original prediction was wrong.

Feingold recently endorsed Obama, after the Democratic presidential candidate clinched his party's nomination.