EC would be dismantled after GOP loss of TX and FL

[Skill and Chance]

I dunno. If the GOP starts losing TX, even narrow margins, there is no way a GOP candidate would come within striking distance to win the NPV, unless CA, NY and IL are trending red. Even if the Mid West, which loses population, largely goes GOP by modest margins. In this scenario, AZ, GA and NC will also vote blue.

There may have been a serious bipartisan attempt to end the EC if W lost the 2004 election by narrowly flipping OH to Kerry. W would still have won the PV under this scenario, and by a larger margin than Gore did in 2000.

Probably the most plausible EC/PV split in favor of Dems would involve the Democrat winning Texas and Florida by a couple thousand votes each while Republicans are coming close in IL and over 60% throughout the rest of the Midwest.  Basically, Republicans would have to start winning the rural Midwest the way Democrats win NYC.

I do think this is more likely than not to happen sometime between now and 2050.  Of course, in such a setting, Republicans wouldn't have enough power to do away with the EC unless the Dems of that era also wanted it gone. 

[Skill and Chance]

The new factor here is that if and when Texas becomes highly competitive in presidential elections, it's likely that Democrats will already have won control the state legislature because of massive GOP self-packing in the rural east and west of the state.  Though they ultimately backed down, Republican swing state legislatures were really playing with fire this November.  It's hard to imagine a remotely close election in which disputing TX's 40+ EV wouldn't change the outcome.