I don’t entirely know that this is fair but if you consider that Romney dropped out of the race and that McCain is not only the symbolic frontrunner but statistically looks like he has the nomination you can probably consider that those who voted for either Romney, Paul or Uncommitted are in fact votes against John McCain. Considering Hukabee won three out of the four contests and then looking at those who cast their votes against McCain you can see that the anti-McCain vote was pretty high.

Kansas
Huckabee won (11,627) with McCain (4,587) in second. The total for Romney, Paul & Uncommitted was 2,919. Not only did Huckabee win big but you can add 2,919 to his commanding lead if you are counting the anti-McCain vote.

Louisiana

Huckabee won (69,665) with McCain (67,609) in second. The total for Romney who came in third and Paul was 18,827.
The anti-McCain vote was 88,492 to McCain’s 67,609.

Washington
Only 87% reporting but McCain is ahead with 3,468 to Huckabee’s 3,226. Paul is in third with 2,799, Romney in fourth with 2,253 and uncommitted ended with 1,729. So the anti-McCain vote was 10,007 to McCain’s 3,468.