Successful political parties are coalitions of interest groups. One way to predict how long a political party can sustain itself in office is to look at the health of its coalitions.
The Reagan-Bush coalition lasted 12 years, from 1980 to 1992 — then conservatives in 1992, led by Pat Buchanan, despaired over George H.W. Bush’s “betrayal” by raising taxes after pledging not to, signing the Americans With Disabililties Act, renewing the Clean Water Act, and other acts they considered too moderate. They sat on their hands in 1992, or defected to Ross Perot.
The Clinton-Gore coalition lasted a solid eight years, and would have sent Al Gore to the presidency in 2000, except for defections by Ralph Nader and/or Green Party supporters in strategic states. Apparently they were disgusted by Clinton-Gore’s “too cozy” relationship with business and corporations, the failure of campaign finance reform, softening of environmental regulations, a sense of government corruption, distaste over Clinton’s sex life, “slick Willy” image, the sense that Clinton-Gore were ethically-challenged, it was time for a change, or just the sense that Al Gore ran a poor campaign, wouldn’t be a good president, or was not likeable.
The Republican coalition under George W. Bush held together through the 2004 election, but then splintered in 2008. The base of the party — many composed of free market fundamentalists — was deeply unhappy with Bush’s intervention in the economy to save big banks “too big to fail,” and the huge deficits he created. Nor was the base all that happy with the “maverick” John McCain, and his support for strict regulation of campaign finance and initially, his support for a path to citizenship for illegal or undocumented immigrants. After the Republicans’ 2008 defeat, this dissatisfaction morphed into the Tea Party, an attempt to purify the party or push it back to fiscal conservatism.
The question for the GOP in 2016 is whether it can heal the rifts within its coalition. Usually a coalition comes together because factions desire to win the presidency trumps the desire to adhere rigidly to principle.
The question for the Democrats in 2016 is similar. Can it hold its coalitions together?