Here's Cillizza at washingtonpost.com:

If the ultimate goal for Republicans is to defeat Obama in 2012, then the Sotomayor pick presents them with a golden opportunity to cast the president as a traditional liberal -- far from the post-partisan figure he was able to present to the American public in the 2008 election.

A couple problems here. Cillizza provides no evidence to back up the claim that the Sotomayor pick would allow Republicans to portray Obama as a “traditional liberal.” (i.e. There's no indication that's how voters see the nomination.) But more importantly, Cillizza doesn't indicate why that would be a problem. I realize Republicans assume that Americans would never elect a liberal president, but why does Cillizza simply accept that GOP premise? Why does he claim that, “Re-defining Obama as a liberal is, without question, Republicans best path to the White House.”

The fact is that 2008 polling indicated that voters viewed Obama as a liberal when they awarded him an electoral landslide election over John McCain. According to an October 2008, Pew Research Center poll, a majority of swing voters viewed Obama as “liberal” (Obama was seen as about as far to the left as John McCain is to the right), and a clear majority of those voters sided with Obama's agenda.

And excuse me, but didn't the entire GOP campaign in 2008 revolve around the fact that Obama was supposedly the most liberal member of the U.S. Senate? Republicans hammered Obama for months as being a liberal, but Cillizza seems to think voters were blind to the candidate's progressive agenda.

Voters weren't somehow fooled during the campaign. They understood Obama represented the liberal candidate and, in overwhelming numbers, they selected him over the conservative one. Cillizza, embracing the center-right myth about American politics, seems to push the idea that if Republicans, between now and 2012, can successfully paint Obama as a liberal than they could seriously dent his chances for re-election.

There's just no proof of that.