If the GOP keeps losing, when would a viable replacement party emerge?

[hopper]

It might happen temporaraly if the Teaparty wing split and ran as a seperate party, however this would not last long, after both parties realize they are just splitting the vote, and allowing the Democrats to win.

No it would probably be a party to the GOP's left flank not to their right.

[Mehmentum]

Well, in a hypothetical scenario (which is unlikely to happen) that the GOP stops being viable, history points in two directions.

1.)  After the Federalists collapsed the Democrat-Republicans splintered, leading to the Democrats and Whigs.

2.) When slavery tore the Whigs apart, the Republicans emerged from coalescing of anti-Slavery Whigs, third parties (mainly the Free Soil Party) and anti-Slavery Democrats.

Scenario 1 would involve some sort of split among the Democrats after the Republicans became mostly irrelevant.  Scenario 2 would involve some sort of split among the Republicans, with one side merging with a third party and winning over a large slice of the Democratic party.

Unlikely, but it would be very interesting.  I would consider myself lucky if I could experience such a political transformation.

[Amenhotep Bakari-Sellers]

The Dem party is the Fed party controlling Prez and Sen and GOP party is the party of the House and state gov.

Its gonna be hard to see that changing. In Israel, the Likud and Kadima party dominates like Dems dominate here.

[Mister Mets]

It would be at least ten years after the GOP loses control of the House, and the Senate. That scenario is unlikely due to the party's edge in both (smaller states are slightly more Republican and the party does better in midterm elections so it's unlikely Democrats will take much of it, geographic sorting has favored Republicans in House redistricting.)

And during this long period, it's likely that Democrats would at some point screw up, allowing a new Republican to get elected to the White House.

[Amenhotep Bakari-Sellers]

Dems have an excellent chance to recapture senate, where the prez states of OH, FL, CO&.NV are up.

But, unfortunately, for the GoP, wallstreet messed up their party's chances and it will take a scandle to get back in.

[ElectionsGuy]

It won't happen. It didn't happen in the 1930's, its not happening now. 

And seriously, so what if they lose another presidential election, they have everything else in the country!

[Amenhotep Bakari-Sellers]

Trump; the Reform Party candidate, is leading frontrunner Jeb, who continues to underpoll Clinton.

So if Trump wins nomination, its still the GOP party, but will have an independent leading presidential race.☺