Democrats and Republicans traded blows Sunday over the Obama administration’s handling of the Sept. 11 attack on a U.S. consulate in Libya, with one Republican senator raising the question of whether politics played a role, and one of the president's top campaign advisers leveling criticism against GOP presidential candidate Mitt Romney. 

Sen. Marco Rubio (R-Fla.) (David Becker/AP)

“What’s most troubling about this is that one of the narratives the Obama campaign has laid out is that [Osama] bin Laden is dead, they’ve bragged about that forever, and that al-Qaeda is in retreat. And you start to wonder, did they basically say ‘do not allow any story to emerge that counters that narrative?’” asked Sen. Marco Rubio (R-Fla.) in an interview on CBS’s “Face The Nation.” “Is that why for two weeks they told us that the Libyan incident in Benghazi was a popular uprising and not a terrorist attack, because it ran counter to their campaign narrative? I hope that that’s not true. But that’s what you start to wonder about.”

Sen. Lindsey Graham (R-S.C.), a member of the Senate Armed Services Committee and one of the most outspoken critics of the administration’s response to the attack in Libya, continued his disapproval Sunday. Graham said he was “totally convinced” the assault, which claimed the lives of four Americans, will go down in history as "one of the most major breakdowns of national security in a very long time."

“I believe this administration has a history of playing politics with foreign policy,” Graham added on "Fox News Sunday," charging that the administration leaked information during previous incidents.  

Democrats pushed back against the GOP charges that the administration offered an inconsistent assessment in the aftermath of the Libya attack, and turned the question about who is playing politics squarely against the Republican side. 

"Obviously this was a tragic event, and the president did call it an act of terror, not just once, but several times," David Axelrod, a senior campaign adviser to President Obama, said Sunday on NBC's "Meet The Press."

"There is only candidate here who has tried to exploit it from the beginning," he added, referring to Romney.

Sen. Dick Durbin (D-Ill.) defended Obama’s response to the attack, saying that the appropriate steps have been taken to get to the bottom of it. 

“They are engaged in a comprehensive investigation of what occurred here. And that’s what we've got to have,” Durbin said on "Fox News Sunday."

Durbin also criticized House Oversight and Government Reform committee Chairman Darrell Issa (Calif.) for releasing documents about security in Libya.

“This idea of Chairman Issa that he's going to dump the names in public of Libyans who are risking their lives to support America and keep us safe in an effort to get a political toehold in this election is unconscionable,” he said.

Obama and Romney will debate a final time Monday in Florida during a 90-minute session that will focus on foreign policy. An NBC News/Wall Street Journal national poll released on the eve of the debate showed Obama and Romney tied at 47 percent among those likeliest to vote. Among all registered voters, Obama led Romney 49 percent to 44 percent. 

Updated at 11:57 a.m.