Senate Republicans up in 2020, ranked by how competitive their states are in the Cook Partisan Voting Index:

1. Susan Collins (D+3)
2. Cory Gardner (D+1)
3. Joni Ernst (R+3)
4. Thom Tillis (R+3)
5. Martha McSally (R+5)
6. David Perdue (R+5)

— ryan teague beckwith (@ryanbeckwith) January 9, 2019