In order for Democrats to retain control of the US Senate, it is urgent that at least one of the following three Republican Senators, all highly disliked for their extreme right wing views, lose reelection in November.
Josh Hawley in Missouri
Rick Scott in Florida
Ted Cruz in Texas
The listing of the above is in the order of the possibility of defeating any of the three, with it being tough to win even one of these seats.
It requires, also, that every Democratic seat be retained, including the most endangered–Sherrod Brown in Ohio, and Jon Tester in Montana.
West Virginia, sadly, will go Republican with Jim Justice replacing the retiring Joe Manchin, but if the Democrats win the Presidency, Tim Walz will be Vice President, and there would be at least a 50-50 tie in the Senate as occurred in the first two years of the Joe Biden Presidency.