Saying his “desire to serve is stronger than ever,” Democrat Russ Feingold announced Thursday a bid for his old U.S. Senate seat against the Republican who defeated him four and a half years ago — Ron Johnson.

A Johnson-Feingold race would be a rare rematch of Senate opponents, offer voters a stark ideological contrast and easily rank as one of the top Senate races in the country in 2016, fiercely contested by both parties.

Feingold made the announcement in a short video shot at his Middleton home, saying he wanted to “bring back to the U.S. Senate strong independence, bipartisanship and honesty.”

He did not mention Johnson in the video or lay out his campaign message in any detail. He said he was focused on the worries people in Wisconsin have about “their economic well-being.” He also raised a familiar Feingold theme — the role of money in the political process.

“People tell me all the time that our politics in Washington are broken and that multimillionaires, billionaires and big corporations are calling all the shots. They especially say this about the U.S. Senate. And it’s hard not to agree,” Feingold said.

I would expect a Democratic pickup here.

Ron Johnson won in a Republican wave year, and he was to some degree an unknown quantity.

Now, he is known as one of the stupidest guys in the Senate, as well as being a teabagger.

Feingold should have run against Walker in the recall, but he was brooding in his tent at the time.