The resolution authorizing military action in Syria is in danger of failing in Congress, Sen. Lindsey GrahamLindsey GrahamGraham: Free press and independent judiciary are worth fighting for The Hill's 12:30 Report McConnell: I’m very sympathetic to 'Dreamers' MORE said Thursday.
Speaking in his home state of South Carolina, the Republican senator said he has serious doubts that Congress will back President Obama’s call for strikes.
Graham said Obama is "well short" of the votes he needs in the House because has failed to make the case to the American people.
“Mr. President, you’ve been uncertain, you’ve been unclear, you’ve changed your mind,” he said. “You have to now come out with a certain plan and a resolve that I have not seen.”
Graham, who is up for reelection in 2014, supports a limited military strike on Syria. He told reporters he plans to host a dinner on Sunday with Vice President Biden and more than a dozen Republican senators to discuss the matter.
Obama is scrambling to round up support in Congress for his Syria plan. With opposition building on Thursday, he canceled a planned trip to Los Angeles so he could remain in Washington to round up votes.
Graham said a strike against Syria would only be successful if it accomplishes three things: changes the balance of power in Syria, helps the opposition and gets other countries in the region involved.
“Saudi Arabia should be paying for this,” he said.
Graham was also critical of Obama's statement that a strike will be effective even if it doesn't come soon.
“When I hear from our military leadership that we can be just as effective 30 days after chemical weapons were used as if it were quick, I’m just baffled,” he said.
“Don’t you believe that [Syrian President Bashar] Assad is moving all of his equipment around? Don’t you believe that he’s preparing for a strike?” he said.