DENVER — It’s a matter of when, not if, President Barack Obama turns to Mitt Romney at the first face-off here Wednesday night and repeats some variation of the same line the president and his campaign have used all year: Mitt, electing you would mean a return to the same policies that got us into this financial mess in the first place.

The attack is Obama’s carefully tested way of saying that Romney would represent a third term for George W. Bush and the 43rd president’s hands-off approach to taxes, spending and regulation that, in the incumbent’s words, “led to the crisis.”