It looks like four Senate races will determine whether Republicans have the kind of night they hoped for two years ago when they considered the 2018 Senate landscape. These races are: Missouri, Arizona, Nevada, and Montana. If the GOP wins three out of the four, it will be something approaching that kind of night.

I don’t have a strong sense of these races yet. However, Henry Olsen seems mildly optimistic about Josh Hawley’s chances in Missouri. He acknowledges, though, that late-arriving returns from St. Louis might put Claire McCaskill over the top, as has happened before.

Olsen sees Arizona trending in Martha McSally’s direction. It was always hard for me to envisage hippie-dippie Kyrsten Sinema carrying Arizona once voters found out about her past. But the polls had me half-convinced that Sinema would win.

She might yet, but McSally looks like the favorite now.

UPDATE: In Arizona, with almost 60 percent of the vote in, McSally has a narrow lead — 49.3 percent to 48.4 percent. [NOTE: I think this report, which I picked up from another site, may be wrong. Politico says only about 20 percent of the vote is in with McSally leading by only about 8,000 votes].

UPDATE: Josh Hawley has been declared the winner in Missouri. This is great news. Hawley is outstanding, just the kind of guy the GOP needs in the Senate.

IN MONTANA: Sen. Jon Tester is out to an early lead. He’s up 54-43, and by 14,000 votes, with 18 percent of precincts reporting. In my view, this was always going to be the toughest of these four races for the GOP.

MONTANA UPDATE: Tester now leads by about 12,000 votes with one-quarter of the precincts reporting.

MORE MONTANA: The Tester-Rosendale is getting quite interesting. Tester’s lead is down to 1.5 percentage points and less than 4,000 votes. That’s with 40 percent of precincts in.

The outstanding Sean Trende adds this perspective: “Of the counties with 0% reporting, Tester won (in 2012): 35%, 67%, 35%, 49%, 46%, 39%, 31%, 35%, 53%, 15%(!!), 72%, 37%, 31%, etc.”

HOWEVER, the outstanding Henry Olsen likes Tester’s chances of hanging on. This was always going to be a tough race for the GOP. For some reason, Montana digs Jon Tester.

THE TESTER LEAD is now about 1,000 votes with half the precincts counted.

THE MCSALLY LEAD is about 12,000 with one-third of the precincts counted.

ROSENDALE PULLS AHEAD: He leads Tester by about 2,000 votes with about 55 percent of the precincts in. However, Nate Silver cautions that there may be lots of votes left from Missoula, and that they could put Tester back ahead. Henry Olsen agrees.

NEVADA RETURNS ARE FINALLY BEING POSTED: Dean Heller, the Republican incumbent, has an early lead in the raw vote. But the analysts I’ve read say these are mostly rural votes and that his margins may be falling short of what he needs.

OH, THOSE LIBERTARIANS: Libertarian candidate Rick Breckenridge pulled out of the race and endorsed Rosendale. Yet, he’s still capturing 3 percent of the vote. That might well tilt the race to Tester.

I”M SIGNING OFF: These three Western states — Arizona, Montana, and Nevada — are proving tough nuts to crack for the GOP. Indeed, Heller seems likely to lose. The other two races seem extremely close.

I’m not surprised that the GOP is struggling in Montana and Nevada. I’m a bit surprised about Arizona but, as I said, the polls had me half-convinced that Sinema would win. Given the vote totals so far, I’m half-convinced now.

The GOP needs to win at least one of these races to position itself nicely to hold the Senate in 2000. But even if it loses all three, it will have 53 seats in 2019 — enough largely to negate moderates Susan Collins and Lisa Murkowski when it comes to confirming judges and cabinet members. (To be fair, Collins hasn’t been much of a stumbling block in this regard).

I don’t know when these three Western races will be resolved, so I’m going to call it a night. Thanks for following my coverage.