Didn't this already happen in 1988-1996?
No.
In 1988, a Republican was elected, and by 1996, there was a sea change in elite behavior and political coalitions in the parties. The New Deal coalition was finally dead below the Presidential level, and the GOP broke through in the South.
Arguably, that happened in 1978-84.
Yeah. Though, one could argue that 1988-1996 was the final death blow. What we will see here, between 2006 and say 2020 is whether the democratic party can reinvent itself or if we are heading to a Right-wing One-Party America, like antebellum America.
No. The Democratic party was basically out of power from 1860 until 1930 (though there were 8 20 years of a Democratic President). Long term, there will be a two party system.
You mean the Gilded Age. Though circumstances were much different than they were today. There was a Civil War and the Dems always had a place where they could get almost uniamious support. Those sort of circumstances simply don't exist. They have been out of power 40 years since 1968, with only 12 years of a democratic president and there hasn't been a civil war to alienate themselves from the majority of the American people or an overwhelingly strong democratic base that always allows them to take half a dozen state by 3:1 in a 20 point rout on presidential election days. You are right, we will have a two-party system. Whether its democrat and republic is an entirely different issue. For exampe, 1904. The dems won like 5 or 6 states by 65% or more of the vote yet were down by 20 nationally. If that were to happen today, you would only win D.C. and the only real battle ground would be M.A....I just don't see how the Democratic Party could survive with no die-hard base through 50 years of opposition.
a 35-65 race today
a 35-65 race 90 years ago.
Federalism just won't isolate a Democratic power out of power for 50-80 years like it used to from extinction causing political futility.
But that means that the Democrats can't run candidates that unacceptable.