In the wake of President Barack Obama's electoral victory, gleeful Democrats believe that the impending "fiscal cliff" has Republicans trapped into finally accepting higher tax rates. But as Senate Minority Leader Mitch McConnell sits for an interview in his Capitol office 48 hours after the election, one thing is certain: He is in no way chastened by Tuesday's results. If Mr. Obama wants fiscal hand-to-hand combat, he will get it.

"Let me put it very clearly," says the five-term Republican senator from Kentucky. "I am not...