No chance of the US becoming a single-party Democrat-led country, with the Democrats incredible ability to snatch defeat from the jaws of victory. But it would be nice if election results swung a little closer to actually reflecting the voters' intent. The disproportionate influence of rural voters, and states with a very small number of residents, gives the Republicans better results than the raw vote should. When the Democrats lose Florida (a larger more urban State) on top of that, things are completely skewed. With Florida as a blue state, and maybe Texas moving that way from demographics, results would come closer to reflecting voter intent.
Or to put it in terms of the current BC election discussion: with proportionate representation the Democrats would have complete control of Congress.
(Of course, for that matter, with FPTP Hillary would be President )
The democrats won't lose florida again after the felon voting bill, and once texas goes blue it is all over for republicans, forever.
There will never be another Republican president once Texas goes blue. Ever.