One thing that does in particular stand out to me that should alarm the Republicans is how several Republican Representatives are planning on vacating their seats in Texas in 2020, some of which will be very contestable. One of them is Will Hurd, the only black Republican in the House and only Republican to have their constituency along the Mexican border. There will also likely be a gain of two seats for the Democrats in North Carolina due to redistricting, with both Republicans of those seats planning to retire after their current term has expired.
I do believe however that Republicans will claim back some lost ground in the Northeast, Midwest and California. Two of the three seats the Democrats hold in Iowa are very much in the tossup area right now, and I would not be surprised if Republicans took back one if not both in November, especially if President Trump performs as well there as he did in 2020. Republicans were absolutely slaughtered in New Jersey- they had 5 of 12 US House seats prior to 2018, and after that election they held one. In California, the Republicans’ count of House seats was slashed from 14 to 7, compared to a rise for the Democrats from 39 to 46.
Considering this is an election which coincides with the presidential election, we can expect greater turnout and for the voting to more accurately reflect each region. I do not think the Republicans will win back the House in 2020, but will cut down on the majority the Democrats have there. 2018 was a very bad midterm for the Republicans, so it makes sense that in 2020 they should gain back some of their strongholds, and those should override the losses they will likely get in Texas and North Carolina. Given how many retirements are being announced plus the lack of initiative the Republican Party is taking, it is clear they have little faith in their ability to win in November, and that will certainly translate to their undoing.
There will be 11 state gubernatorial elections this year. I argue that there are only two that you should really pay any attention to, which are Montana and North Carolina. The other 9 if you are particularly curious are Delaware, Indiana, Missouri, New Hampshire, North Dakota, Utah, Vermont, Washington, and West Virginia. Despite most of them being solid for one party you might be surprised to find that two of those governors (Phil Scott of Vermont and Chris Sununu of New Hampshire) are both actually Republicans and hold some of the highest approval ratings of any governors in the nation. Of course there is always a possibility that one or more of these 9 could become contestable, but given each of their merits I would at the moment argue that there is little point in focusing on the highly unlikely.
Montana is an interesting state as it will overwhelmingly vote Republican for the presidency but is actually a battleground otherwise, especially in the Senate (Democrat Senator Jon Tester won reelection in 2018) and the governorship (Democrat Steve Bullock has won so many elections he is term limited and cannot run again). Overall however it should be lumped with the Republican spectrum. The Democrat frontrunner is for now the current Lieutenant Governor Mike Cooney, but there is also report that former Democratic Governor Brian Schweitzer could enter as well. On the Republican side the only really well known runner is Greg Gianforte, the current Republican Representative of Montana infamous for body slamming a reporter. Whether or not the Republican nominee is Gianforte, I would say to put your money where the Republican is.
Last but not least is North Carolina. Most polls indicate current Governor and Democrat Roy Cooper will beat Lieutenant Governor and Republican Dan Forest (Forest has not yet achieved the nomination, but he is in a strong enough position that I will treat him as the Republican nominee). Despite that I say Forest will win come November. He is pretty popular for the political polarization of North Carolina, and Roy Cooper is not. In my opinion Cooper is Barack Obama without the charisma, which is not a good fit for my state. If Roy Cooper hardly beat Pat McCrory four years ago (and he was not very popular), then he will definitely have a tough reelection bid to win against the likes of Forest. The only real advantage I see him having is the power of incumbency.