The Republicans have glommed on to a neat rhetorical trick: When Barack Obama does something indisputably admirable or effective, simply pretend that he had nothing to do with it.

This ploy was first trotted out in the aftermath of Moamar Qaddafi’s downfall in Libya, when Obama’s former presidential rival, Sen. John McCain, gave all the credit to the French.

Now Mitt Romney, this year’s presumptive GOP nominee, is waving off Obama’s role in the killing of Osama Bin Laden—the president’s signal national-security achievement—by chortling that “any thinking American would have ordered the exact same thing,” even Jimmy Carter.