(CNN) - The action is clearly on the Democratic side, but Republicans also held primaries in Indiana and North Carolina Tuesday.
Despite being his party's presumptive nominee for nearly three months, roughly a quarter of Republicans in North Carolina and Indiana showed up to vote against the Arizona senator.
With nearly all precincts reporting, McCain won 74 percent of the vote in North Carolina. Mike Huckabee, who dropped out of the race two months ago, scored 12 percent. Ron Paul, who never quite officially ended his White House bid, registered 7 percent, and Mitt Romney got 5 percents.
The story was only slightly better for McCain in Indiana. There he scored 77 percent of the vote, while Huckabee registered 12 percent, and Paul garnered 7 percent. Nearly 5 percent of North Carolina voters said they did not have a preference.
McCain faced similar results in the Pennsylvania primary two weeks ago - the first contest after Huckabee officially dropped out of the race. There the party's presumptive presidential nominee won only 73 percent of the vote.
Is this a troubling sign for McCain, who has long faced resistance from the conservative wing of his party?
Then-Gov. George W. Bush faced similar results, though slightly better, in these three states long after he was the clear nominee in 2000. In North Carolina, he won 78 percent of the vote, in Indiana he got 81 percent, and in Pennsylvania he won 73 percent of the vote.