Here are the vote percentages of Republican senators in contested primaries this year:
Mitch McConnell: 60.2
Lindsey Graham: 56.4
Thad Cochran: 51
Lamar Alexander: 49.9
Pat Roberts: 48
Compare with this chart of recent history:
If GOP senators want to keep surviving by the skin of their teeth in primaries, then they should continue to support amnesty for illegal aliens. If not, they need to mend their ways.