Paul's assessment comes on the same day that House Republican and Democratic leaders said they would support a Syria resolution. 

Paul stressed that it would be a mistake to approve a Syria resolution in any chamber, since most people oppose military action of any size against that country. But he said his best guess is that the Senate will approve it.

"People up here are so out of touch," Paul said. "These senators who are going to vote for this, they need to go out and talk to their people, or look at what their people are saying, because people do not want to get involved in Syria.

"Despite what the people want, their senators are going to vote the opposite way. I have a bad feeling."

Paul also said he hasn't decided whether he'll try to filibuster the resolution.

"Whether there's an actual standing filibuster, I've got to check my shoes and my ability to hold my water," he said. "We'll see, I haven't made a decision on that."

In March, Paul held a standing filibuster for nearly 13 hours to protest the Obama administration's failure to clarify whether it is allowed to kill a U.S. citizen on U.S. soil when they don't pose an immediate threat. After his filibuster, the administration finally gave him the clarification he sought.

Paul spoke just moments after questioning Secretary of State John KerryJohn Forbes KerryShould President Trump, like President Obama, forsake human rights in pursuit of the deal with a tyrant? GOP Senate report says Obama officials gave Iran access to US financial system Democrats conflicted over how hard to hit Trump on Iran MORE about whether the Constitution allows the administration to use the military without the permission of Congress. Paul argued that the Constitution gives that authority to Congress, and implored Kerry to say that the administration would not act if Congress rejects Syria language.

"Stand up for us and say you're going to obey the Constitution, and if we vote you down — which is unlikely, by the way — but if we do, you would go with what the people say through their Congress, and you wouldn't go forward with a war that your Congress votes against," Paul said. "Can you give me a better answer, Secretary Kerry?"

Kerry argued that the Constitution allows the President to use the military, and said Paul should be glad that Obama would in fact be following the Constitution even if he ordered a strike against Syria without congressional permission.

"I can't give you a different answer than the one I gave you, I don't know what the president's decision is," Kerry said. "But I will tell you this: it ought to make you proud because he still has the constitutional authority."

Paul shot back that the administration is trying to argue that limited military operations are not acts of "war" that need to be approved by Congress.

"They didn't say big war, small war, they didn't say boots on the ground, not boots on the ground, they said 'declare war,' " Paul said of the drafters of the Constitution.

"If we do not say that the Constitution applies, if we do not say explicitly that we will abide by this vote, you're making a joke of us. You're making us into theater."

Paul and Kerry also sparred on whether the situation would be made better or worse by striking Syria. Paul said there are many unknowns that could lead to more strife in the region if the U.S. attacks, including Syrian attacks against Israel.

But Kerry disagreed and said failing to hold Syria accountable for using chemical weapons would only embolden Syrian leaders to use them again.

"If the United States of America doesn't hold him accountable on this, with our allies and friends, it's a guarantee Assad will do it again, a guarantee. And I urge you to go to the classified briefing and learn that."

Kerry and other officials will brief committee members tomorrow in a closed-door hearing, and other House and Senate hearings are scheduled for Wednesday on Syria.

Before the Senate hearing ended today, Committee Chairman Robert MenendezRobert (Bob) MenendezSchumer: Obama 'very amenable' to helping Senate Dems in midterms The Hill's Morning Report: Can Trump close the deal with North Korea? Senate must save itself by confirming Mike Pompeo MORE (D-N.J.) said he thinks it's likely that the panel will consider a resolution authorizing limited military strikes against Syria.