WASHINGTON -- President Barack Obama's Senior Adviser David Plouffe called former House Speaker Newt Gingrich's comments on the shooting of Trayvon Martin "reprehensible" on Sunday, saying they came from a man who was "clearly in the last throes of his political career."

On Friday, Obama broke his silence on the shooting of the unarmed African-American teenager in Florida, a case that has launched a national movement.

"If I had a son, he'd look like Trayvon," Obama said, underscoring how the issue affected him on a personal level. "I think [Trayvon's parents] are right to expect that all of us as Americans are going to take this with the seriousness it deserves, and we are going to get to the bottom of exactly what happened."

Gingrich took exception with Obama's comments during a radio interview later on Friday, saying they were "disgraceful."

"It's not a question of who that young man looked like," he said. "Any young American of any ethnic background should be safe, period. We should all be horrified, no matter what the ethnic background. Is the president suggesting that, if it had been a white who'd been shot, that would be OK, because it wouldn't look like him? That's just nonsense."

On ABC's "This Week," Plouffe said he thought the president had spoken out "very powerfully." He noted that there has been broad bipartisan agreement that there needs to be a thorough investigation of the incident, and of whether the shooter, George Zimmerman was truly acting in self-defense and whether race was at all involved.

"Those comments are reprehensible," Plouffe said of Gingrich's response. "And, you know, Speaker Gingrich is clearly in the last throes of his political career. And, you know, you can make a decision whether to go out with some shred of dignity or say these irresponsible, reckless things, and he's clearly chosen the latter path, and that's unfortunate for the country."

Zimmerman, a neighborhood watch volunteer, has so far avoided arrest under Florida's Stand Your Ground law, which allows an individual who feels threatened to "stand his or her ground and meet force with force, including deadly force." Critics say that the law did not apply in this case, because Martin was unarmed and, according to the recording of a 911 call, Zimmerman pursued him.

Similar laws are in place in about 20 states. Plouffe said on Sunday that he expects that states will be looking at these laws as the controversy plays out.

"But right now, our focus ought to be on sympathy for the family and then making sure an investigation is done thoroughly," he said. "And there seems to be, you know, agreement on that across the partisan divide. You have Democrats and Republicans, independents, everybody, saying let's look into this. And I think that's what's going to happen."

UPDATE: 12:10 p.m. -- On CNN's "State of the Union," Plouffe criticized former Sen. Rick Santorum's reaction to Obama's comments on the Martin shooting.

Santorum said on Friday that the president should "not use these types of horrible and tragic individual cases to try to drive a wedge in America."

Plouffe called both Gingrich and Santorum's remarks "irresponsible," adding, "I think those comments were really hard to stomach, really, and I guess trying to appeal to people's worst instincts."