For a big winner he sure is weak

Despite getting drubbed in Wisconsin this week, Donald Trump has won more votes than any other Republican candidate this year. So, he’s doing OK, right? Well, for all the talk that unbound delegates and quirky convention rules could prevent Trump from winning the GOP nomination, it’s easy to forget that Republican voters also play a part. Trump’s 37 percent of the cumulative primary vote and 46 percent of delegates won so far may sound impressive, but his percentages make him the weakest Republican front-runner, at this point in the process, in decades.

Of course, a front-runner is still a front-runner, but by historical standards Trump is limping along — hence the increased chances of a contested convention.

This is the seventh Republican primary in the modern era (beginning in 1972) without an incumbent president in the race; here’s the cumulative vote percentage that each eventual nominee received over the course of the primary season in those seven campaigns:

Past GOP nominees such as George H.W. Bush in 1988, George W. Bush in 2000, Bob Dole in 1996 and Ronald Reagan in 1980 had bigger shares of the vote at this point, even if they started out slowly. You’ll also note, however, that the two most recent Republican nominees, John McCain and Mitt Romney, weren’t doing too much better than Trump is now.

McCain and Romney, though, were far ahead of Trump at this point in the delegate race. All the eventual nominees studied here won a majority of the delegates allotted1 by this date. Trump remains short of a majority.

You’ll also note that past nominees tended to increase their delegate and vote leads from this point forward, mostly because their rivals had faded or dropped out. In 2008, McCain vanquished Romney by early February and Mike Huckabee by early March. About this time four years ago, Romney lost his main competitor, Rick Santorum, after winning the Wisconsin primary. That left McCain and Romney with an easy road to winning larger and larger shares of the delegates and votes in the remaining contests.

From Thursday to Saturday, Trump suffered setbacks in Colorado, Iowa, Michigan, South Carolina and Indiana that raise new doubts about his campaign’s preparedness for the long slog of delegate hunting as the GOP race approaches a possible contested convention. He lost the battle on two fronts. Cruz picked up 28 pledged delegates in Colorado. In the other states, rival campaigns were able to place dozens of their own loyalists in delegate spots pledged to Trump on the first ballot. This will matter if Trump fails to win a majority of delegates on the first ballot in Cleveland, as his delegates defect once party rules allow them to choose the candidate they want to nominate.

Trump’s campaign mounted a haphazard campaign for delegates in Colorado, where hundreds ran to be at large representatives in Cleveland at the state convention in Colorado Springs. The frontrunner’s advisers repeatedly instructed supporters to vote for the wrong candidates—distributing the incorrect delegate numbers to supporters. Cruz, who traveled to address the convention, swept the state’s 34 delegates on the back of a disciplined organizing effort, that included text message and video displays advertising his preferred slate.

The situation in Louisiana infuriated Mr. Trump, who threatened this week to sue the Republican National Committee over it.

But when Mr. Priebus explained that each campaign needed to be prepared to fight for delegates at each state’s convention, Mr. Trump turned to his aides and suggested that they had not been doing what they needed to do, the people briefed on the meeting said.