Supporters of Republican gubernatorial nominee Ed Gillespie watch as he delivers a concession speech at an election night watch party at the Richmond Hilton. (Ricky Carioti/The Washington Post)

I didn’t see that coming.

The data, the news flow and my own myopia missed Democratic gubernatorial nominee Ralph Northam’s thrashing of Republican gubernatorial nominee Ed Gillespie at the polls on Tuesday.

And if that weren’t enough of a miss, the massive gains Democrats made in House races, some of which (despite assertions from would-be House Speaker Kirk Cox) won’t be decided until after recounts, caught me and just about everyone else by surprise.

Congratulations, then, to the Democratic ticket and the slate of House candidates who through their victories have ensured that the 2018 General Assembly session will be exceedingly interesting.

And brickbats to me for doubting it could happen on the scale it did.

So what happens now?

Northam has to show he can govern. There’s little doubt he has that ability, being a seasoned and capable politician. One of his biggest challenges won’t be policy, however. It will be managing the ambitions of other Democrats (Attorney Gen. Mark Herring, Lt. Gov.-elect Justin Fairfax and Richmond Mayor Levar Stoney, for starters) who have designs on his new job.

How Northam brokers that potential clash will be fascinating to watch.

So, too, will the governor-elect’s desire to seek Medicaid expansion. While the issue went nowhere with Republicans in control of the House, that’s all different come January.

If, as is possible, recounts split House control 50-50, some sort of power-sharing agreement will have to be reached. Getting there could be a monumental fight in itself. But Virginia has experience with power-sharing in the House and the Senate.

Whether an agreement results in one party getting the speakership and the other party getting the most powerful committee chairmanships or something else entirely remains to be seen.

And even if recounts result in Republicans maintaining a single-seat advantage and chamber control, they won’t necessarily be able to stand in the way of issues like Medicaid expansion, looser abortion rules or gun control.

If anything, a single-seat GOP advantage could be Kirk Cox’s worst nightmare. He would have the speaker’s gavel, but control over both the House and his caucus? Perhaps not so much.

Speaking of the Virginia GOP: Where does it go from here?

All signs point deep into the wilderness. Since its high-water mark in 2009, when the party swept all three statewide offices, it has gone 0-10 in statewide elections.

That’s Cleveland Browns-level futility.

That should mean the state party’s leadership team would either gracefully exit on its own or be tossed over the side at the next state central committee meeting. Changing party leaders won’t solve the party’s problems. But the symbolic value is very real.

Who could fill the positions of party chairman and party executive director? The GOP bench has gotten remarkably thin in recent days. Competent staffers may be hard to find, and those who are found may be unwilling to serve.

But not all is bleak for the GOP. It could pick a former officeholder to take the chairman’s job — I’m looking at you, Bill Bolling. It may be time for the “Hanover Hun” to clean house.

Republicans in general also need to look very hard at their strategy and candidates heading into next year’s congressional elections.

Rep. Barbara Comstock, a consistent target for Democrats, will be under even greater pressure in 2018. Comstock is a talented politician who can and will run a formidable reelection effort. She will need all of her considerable skills to survive a Trumpian mid-term election.

And then there is Corey A. Stewart, the only declared GOP challenger to Sen. Tim Kaine (D).

Stewart also wants a change in state party leadership. He heaped scorn on Gillespie for running away from the president.

Here’s a prediction: If the GOP nominates Stewart against Kaine, Kaine wins handily — and helps take out at least a couple of incumbent GOP House members in the process.

How deep do the political woods go? Without a big change in course, Virginia Republicans might find they are endless.