Sen. Rand Paul (R-Ky.) said the prospects of the House approving a military strike in Syria are "50-50."
Paul expressed confidence a Senate vote would be successful, but along with other lawmakers on Sunday voiced skepticism the House would follow suit.
Paul said that while it's "pretty apparent there was a chemical attack," he still would oppose military engagement in Syria because it would "accelerate the misery" in the region.
"I think all of the bad things that you can imagine are more likely if you get involved in the Syrian civil war," he said.
He added that he only sees a justification for U.S. military engagement when U.S. interests are involved, and he doesn't see that standard holding in Syria.
Though Paul said that he was "proud" of President Obama for seeking congressional approval, he slammed Obama for not engaging enough with Russia and China to try to orchestrate regime change in Syria.
And he said if Obama moves forward with military action absent congressional approval, he would simply be showing off his "machismo."
"When you set a red line that was not a good idea in the beginning with and now you're going to try to adhere to it and show your machismo, I think then you're trying to save face and really adding bad policy to bad policy," he said.
Earlier Sunday in appearances on Fox News, Rep. Peter King (R-N.Y.) and Sen. Jim Inhofe (R-Okla.) said Congress was unlikely to grant President Obama’s request for a military strike against Syria.
But Rep. Mike Rogers (R-Mich.), the House Intelligence Committee chairman, was among the lawmakers saying he thought Congress would approve action.