Mitt Romney’s campaign has hit back against the delegate math in Rick Santorum’s strategy memo. Most persuasive argument: Romney can clinch by winning only 47 percent of the remanining delegates, while Santorum and Newt Gingrich need 65 to 70 percent. With most of the remaining winner-take-all states favoring Romney, that’s a tall order.

Least persuasive argument: many of the delegate tallies already take into account Santorum’s advantage winning delegates from caucus systems at county and state conventions. Yes and no. Obviously, that’s true in some projections (e.g., Minnesota) but what about places like Colorado and Iowa? Once the main event is over, it’s possible that in some areas Santorum’s main competitor in delegate-hunting will be Ron Paul.