Weekly Standard: “The basic math of the 2018 Senate elections shows a challenge for Democrats. In order to win control of the upper chamber, the party need to successfully defend all 26 of its seats up for election (some of which are in highly red states like Missouri, Indiana, North Dakota, West Virginia, and Montana) while taking the open seat in Arizona and unseating Dean Heller in Nevada.”

“If Republicans manage to beat Democrats in just one of those races, then either Tennessee or Texas (both of which are very red) will likely become a must-win. If Republicans manage to beat Democrats in two or more of those races, then they’re very likely to keep control of the Senate.”