At Pew, Drew DeSilver makes a key observation about multi-ballot
conventions:
Republicans opposed to Donald Trump as their party’s nominee are pinning most of their hopes on stopping him at this summer’s national convention in Cleveland. Although Trump has more delegates than his two remaining rivals (760 or so by our count), he needs at least 1,237 to win the nomination on the first ballot. Texas Sen. Ted Cruz and Ohio Gov. John Kasich are hoping to win enough delegates in the remaining primaries to keep Trump from reaching that magic number. After the first ballot, the thinking goes,most delegates become “unbound” and can vote for other candidates. They could even draft a completely new candidate (though House Speaker Paul Ryan, a frequently mentioned “dark horse” alternative, ruled himself out earlier this week).
If all that sounds a bit like a Hail Mary pass, bear in mind that these situations have happened before. Not recently, mind you (the last time was at the 1952 Democratic convention), but they have happened. Since the Civil War there have been eight Republican and 10 Democratic conventions that took more than one ballot to pick a nominee. In only seven of those 18 instances did the first-ballot leader win the nomination.
