From an interview with Fox News:
Let me just say that the Senate majority has not been a certainty at any point this cycle. We always knew from the beginning, and I’ve said consistently there’s going to be a dog fight. The other thing that’s not new is that we’re being outspent these days. We were outspent in 2016 and held the majority. We were outspent in 2018 and held the majority. We were outspent in every single race that we won in 2018 — and we were outspent.
Now, we do have a lot of exposure. This is the big class that took the majority in 2014, so we have a lot of people up. Twenty-three seats to defend. They only have 12. We have one really good pick up opportunity in Alabama and another really good pick up opportunity in Michigan. Everywhere else we’re on defense. So whether you’re on offense or defense sort of depends upon how you did six years before. It’s going to be a fight to the finish or like a knife fight in an alley.