"If I can raise the money, I'll do it," Sen. Lindsey Graham (R-S.C.), pictured here at the Republican Leadership Summit on April 18, 2015 in Nashua, N.H., said of a presidential run. (Darren McCollester/Getty Images)

Sen. Lindsey Graham (R-S.C.) said his decision on whether he'll run for president depends on whether he can raise enough money, but he said there's a "91 percent" chance he will.

"If I can raise the money, I'll do it," he said on "Fox News Sunday with Chris Wallace." He added, "I think I got a good message, I think I've been more right than wrong on foreign policy. I've criticized the president for leading from behind, being weak and indecisive. I've been a problem solver in Washington, and I think I've got something to offer the party in Washington."

He said he would make a decision by May.

South Carolina polls show Graham behind Scott Walker, Jeb Bush and Ted Cruz in his home state. The polls found that 55 percent of South Carolina voters wouldn't vote for him for president.

Graham shrugged off the numbers. "If I'm on the ballot, I'm going to win South Carolina," he said, pointing to his previous wins there.

Wallace asked Graham about some of his stances, such as on taxes and climate change (he is for raising some taxes and believes that climate change is real), that put him at odds with some Republican voters. The senator characterized his positions as common sensical.

"I'd like to clean up the air and the water, become more energy independent," he said of climate change. "I reject the cap-and-trade solution of Al Gore."