With Election Day looming one short year away, Mr. Obama’s most effective heat shield turns out to be his loyal opposition: Republicans scrapping to unseat him and getting lampooned for it by late-night TV comics.

The jokes range from blistering to silly to simply sophomoric. But it should be all the same to Mr. Obama: They’re not targeting him…

Things were very different a year ago, when Democrats got what Mr. Obama called “a shellacking” in the election, with Republicans capturing the House of Representatives and scoring gains in the Senate. Democrats got a shellacking in late night, too.

“While you were applauding, three more states turned red,” Mr. Letterman said on his Nov. 2, 2010, Election Day show. Two nights after the Democrats’ crash landing, he joked that “experts are now saying we won’t know what happened to the Democratic Party until we find the black box.”