If you're a football fan, you've seen it happen. A coach bursts into prominence by using offensive or defensive innovations to produce victory after victory, championship after championship. For a long time, he's regarded as one of the best. And then, something happens.
First it's an upset loss here and there. Then it's a decline to mere respectability or mediocrity. The coach fires assistants, widens his search for players and tries new schemes. But nothing helps. Soon, the onetime genius is a has-been, out of ideas and out of work.
But it doesn't happen only in football. It also happens in politics. For a long time, the Republican Party had a proven formula for presidential elections, winning seven out of 10 times from 1968 through 2004. But after two straight losses, it suddenly looks badly out of touch with the electorate.
One explanation is that Republican candidates have done so much to hurt themselves -- insulting women with obtuse remarks about abortion, alienating Latinos by demonizing illegal immigrants and fighting same-sex marriage despite the public's shift in favor of it.
But the bigger problem is that some major factors that once propelled the GOP to victory no longer exist and the party has failed to replace them. Remember Kodak? It was the leader in the film business -- only to find that even the best film is obsolete in the digital era.
A generation ago, what was the biggest motivation for electing Republican presidents? The military threat and ideological challenger of world communism. Americans might not have been willing to buy a used car from Richard Nixon, but they trusted him more than Hubert Humphrey or George McGovern to resist the red tide.
Ronald Reagan won in 1980 partly because the Soviets invaded Afghanistan and were seen as surpassing us in military power. Jimmy Carter, whom he defeated, said he was surprised that Soviet leader Leonid Brezhnev had lied to him, which would not have surprised Reagan.
Carter had signed a controversial nuclear arms control agreement. Reagan embarked on a military buildup to bankrupt the Soviets, while providing covert aid to the Afghans fighting against them. Whatever voters thought of the Republican Party, they never thought it was soft on communism. They were not always sure about Democrats.
Nixon also made the most of another fear -- of crime and violence. In 1968, he ran as the candidate of "law and order" against a backdrop of rising street crime and urban riots. In the 1970s, the joke was, "A conservative is a liberal who's been mugged."