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 allotted 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.

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Trump isn’t so lucky. Ted Cruz is almost certainly going to fight hard all the way to the last primaries on June 7 and beyond. (John Kasich might, too.) Unlike Santorum, who ran out of money after losing Wisconsin in 2012, Cruz is flush with cash. That doesn’t necessarily mean Trump won’t end up with a higher share of support overall than he has won in primaries so far. He should add to his total in the New York primary later this month, for example. But after New York, the calendar becomes considerably tougher for him.

Unless something radically changes, Trump will finish the primary season with the lowest percentage of the primary vote and the lowest share of delegates of any Republican presidential primary vote leader since caucuses and primaries became the main method for selecting nominees.