A top Republican senator is conceding defeat in the debate with President Obama over how best to avoid the “fiscal cliff,” accepting that tax increases now appear inevitable.

“Hats off to the president. He stood his ground. He’s going to get tax-rate increases,” Sen. Lindsay Graham of South Carolina said on “Fox News Sunday.”

“He won,” Mr. Graham said, a blunt assessment of the political environment on Capitol Hill now less than 48 hours before massive spending cuts and tax increases on most Americans go into effect on Jan. 1.