Republicans are talking about the chances of a brokered convention, where their nominee is chosen in smoked filled back rooms. The betting site Intrade currently has the odds at 5 to 1.
For the over 30 years the Republican convention has been a coronation. With the nominations wrapped up early the conventions could be choreographed affairs with all the drama of a wet dishrag drying in the sun. In 1976 there was something of a competition between Jerry Ford and Ronald Reagan but there was no real brokering. Incumbent Ford was the establishment candidate and was always assured the bulk of the uncommitted, professional politician delegates.
1952 - Eisenhower and Taft
1920 - Warren Harding
Party leaders started meeting to find some third choice, some pleasant fellow that nobody hated. They settled on Harding. Everybody liked him. Lowden's backers liked him because, while he was a randy drunk, he supported Prohibition for everyone else. After ten ballots they finally picked the dumbest man to every hold the office, before George Bush.
1880 - Garfield (not the cat)
Grant is not a perfect match from Romney. Grant (Stalwart faction) was not rich, he need a third term as president to steal some funds for his retirement. Blaine (Half Breed faction) is a good copy of Gingrich. Both were Speakers of the House, excellent public speakers, and both were tainted by corruption. While Sherman did author the Sherman Anti-Trust Act he otherwise, like Santorum, accomplished mostly nothing during his career.
The convention got stuck, Grant's people would never vote for Blaine (and vice versa) while Sherman's supporter couldn't stomach voting for either of those two jerks. Ballot after ballot was cast with no decision. Finally, the Half Breeds decided to offer up a Sherman supporter as a compromise candidate. After 35 ballots over two days the convention finally chose James Garfield and to heal the party they picked Grant supporter Chester Arthur as Vice President.
A note to Chris Christy here is offered. Garfield was assassinated after four months in office by a member of the Stalwart faction.
1924 - Democratic Convention