Having won DC’s 16 delegates and at least 28 of Maryland’s 37 delegates tonight,* Romney now has 616 delegates, if we use the AP’s count coming into the night. That’s 57.4% of all delegates.

In order to get to the threshold of 1,144 delegates, Romney has to win only 528 of the remaining 1,213 delegates — or 43.5%. Put the other way around: the non-Romneys have won 42.64% of all delegates to date, and in order to block Romney from winning before the convention, they would need to win 56.6% — an improvement of 32.6%.