Michael Barone: Don't look for either party to have a brokered convention next year
With multiple serious candidates competing for each party's nomination, it's possible that no candidate will emerge from the caucuses and primaries with a majority of delegates in each party.
The theoretical possibility is greater in the Democratic Party, because it tends to allocate delegates by proportional representation. If you make a straight-line extrapolation from current polls in Iowa and New Hampshire, assume that the candidates there get a bounce from their showings and calculate the number of delegates per candidate in succeeding contests, three or four candidates would emerge with votes in excess of the 15% threshold required in most contests for delegates, and none would end up with a majority.
That's not a scenario most political insiders expect to happen. More likely the race will boil down to two candidates, one of whom will end up with a majority of delegates. Still, it's theoretically possible.
Similarly, though Republicans tend to use winner-take-all rules to allocate delegates, one could imagine that four or five candidates will be closely enough matched to prevent any one candidate from winning a majority of delegates. Not likely, but possible.
But even if these unlikely scenarios occur, you're not going to see an old-time convention in Denver in August or in St. Paul in September. To understand why, you have to understand what conventions used to be, and how they operated.
The old-time convention was a medium through which men who seldom saw each other and often didn't know each other could communicate, negotiate and reach an agreement. And not always productively.
At the first national convention--held in Baltimore, Md. by the Anti-Masonic Party in September 1831--116 delegates from 13 states nominated Attorney General William Wirt, a former Mason who found nothing repugnant about Masonry.
Three months later a group of 168 delegates from 18 states opposed to President Andrew Jackson met and unanimously nominated Henry Clay. Jackson's backers, with Martin Van Buren pulling the strings behind the scenes, staged the first Democratic National Convention in May 1832. It concurred in nominations Jackson had received from state legislative caucuses and then nominated Van Buren for vice president.
Political parties were then and remained for years alliances of state parties, many of which had little in common. The Whigs, as Jackson's opponents came to be known, had no national convention in 1836 but nominated three regional candidates to oppose Van Buren in 1836; Michael Holt's definitive "The Rise and Fall of the American Whig Party" is an account not of a national party, but of separate state parties....
Even in the days of old-time conventions, multiballot contests were less common than legend would have it. The Democrats have gone on to multiple ballots in just 15 of 49 national conventions. The Republicans, who held their first convention in 1856, in just 10 of 44 national conventions. Since the 1920s the parties have had only four multiballot conventions, the Democrats in 1932 and 1952, the Republicans in 1940 and 1948 (you may note that only in the first of these did the nominee win in November).
The convention of legend was, of course, the 1924 Democratic National Convention at the old Madison Square Garden. The Democrats were sharply split between Southern and rural Drys and big city machine Wets. The minority report condemning the Ku Klux Klan, then in an expansionary period, was rejected by a margin of 543 3/20 to 542 7/20. The candidate of the South, William McAdoo, led the "happy warrior" big city leader Al Smith by 431 to 241 on the first ballot, but was still short of the majority and far from the necessary two-thirds. By the 50th ballot McAdoo had gained 30 votes and Smith 79; on the 100th ballot McAdoo fell behind John W. Davis, former solicitor general and ambassador to Britain (and, 30 years later, lead lawyer for the losing side in Brown v. Board of Education). On the 101st ballot McAdoo and Smith dropped out and Alabama's Oscar Underwood finished second behind Davis; on the 103rd Davis was finally nominated. All of this in a sweltering hall where delegates were covered in sweat, covered in epic style by the Baltimore Sun's H. L. Mencken....
The parties will continue to hold national conventions, because the experience of the last 25 years tells them that they can be (though aren't always) effective advertisements for their nominees, who have of course been chosen months before. The vice presidential nominees also have been chosen before the convention in most cases. But even if the caucuses and primaries of one or both parties in 2008 fail to give any candidate a majority of delegates, no one is going to wait for the convention to negotiate an outcome.