It's become a somewhat tired story line, but John McCain continues to struggle in trying to rack up dominant showings in these remaining "straggler primaries." Yesterday he went one-for-two.

In the Kentucky primary he managed only 72 percent of the vote against then-Gov. George W. Bush's 83 percent back in 2000, the last contested Republican primary. Even Bob Dole, the man with whom McCain is drawing increasing parallels, managed 74 percent in Kentucky in 1996.

In Oregon, McCain had a better showing, grabbing 83 percent of the vote, while Bush got 84 percent in 2000. In 1996 the Oregon primary was far earlier in the calendar year, so Dole's 51 percent take is not a fair comparison.

Overall, McCain has now won 46 percent of the 20.2 million votes cast in the Republican primaries to date, according to www.thegreenpapers.com, one of the best sites for tracking these things. That compares unfavorably with Bush's 62 percent in 2000 and Dole's 59 percent in 1996.

The McCain campaign has said the comparisons are unfair because the Democratic contest this year is so engaging it is potentially drawing McCain voters away from the Republican primaries. They point to exit polling that suggests many of the voters in the Democratic primaries will not be able to stomach the eventual Democratic nominee, and will consider voting for McCain.

One piece of evidence that McCain's folks are right is the protest vote in Oregon, which in both 2000 and 2008 featured a maverick Republican trying to force reform on his party: This year it was Rep. Ron Paul, and in 2000 it was Ambassador Alan Keyes. Paul took 14 percent of the vote in Oregon this year, while Keyes took 13 percent in 2000.

— Stephen Dinan, national political reporter, The Washington Times