White House adviser David Plouffe assailed Newt Gingrich and Rick Santorum today after the Republican presidential candidates suggested that President Obama is politicizing the shooting death of 17-year-old Trayvon Martin in Florida.

"This Republican primary at some points has been more of a circus show, a clown show," Plouffe said on CNN's State of the Union. "And those two comments are really irresponsible. I would consider them reprehensible."

Gingrich criticized Obama -- who said Friday that "if I had a son, he would look like Trayvon" -- for citing the victim's race.

"Is the president suggesting that if it had been a white kid who had been shot, that would be OK because he wouldn't look like him?" he said. "It's just nonsense. Dividing this country up – it is a tragedy this young man was shot."

Santorum said Obama was "politicizing" the issue: "What the president of the United States should do is try to bring people together, not use these types of horrible tragic individual cases to try to drive a wedge in America."

Plouffe said the GOP candidates couldn't be more wrong.

"I think the president spoke movingly about this tragedy, as a father, made it clear that there's an investigation going on," he said on CNN. "So I think those (Republican) comments were really hard to stomach, really, and I guess trying to appeal to people's worst."

Speaking specifically about Gingrich on ABC's This Week, Plouffe said the former House speaker is "clearly in the last throes of his political career."

"You can make a decision whether to go out with some shred of dignity or say these irresponsible reckless things," Plouffe said. "And he's clearly chosen the latter."

The Justice Department is investigating the shooting death of Trayvon by a neighborhood watch volunteer who claimed he was acting in self-defense.

Obama said Friday that the nation needs to do some "soul searching to figure out how does something like this happen. And that means that we examine the laws and the context for what happened, as well as the specifics of the incident."

All of the Republican candidates said officials need to get to the bottom of the case.

Mitt Romney: "The shooting of Trayvon is a terrible tragedy -- unnecessary, uncalled for, and inexplicable at this point. What we've heard from the media reports suggest that it's entirely appropriate for the district attorney to be looking into this and to have called a grand jury and find what the facts are."

Santorum: "It's chilling to hear what happened and, of course, the fact that law enforcement didn't immediately go after and prosecute this case is another chilling example of obviously horrible decisions made by people in this process."

Gingrich: "I think we have to recognize that all too often there are neighborhoods in which young people don't have a chance to pursue happiness, they don't have a decent future."

The president's full comments Friday: