Larry Sabato has released his Crystal Ball ratings for the 2018 senate races.  He is predicting that Pennsylvania is likely to keep Senator Bob Casey.  

Sabato acknowledged that Trump won Pennsylvania in 2016, but argues that Casey’s previous wins will help him.  In 2012 Casey ran ahead of Obama in the state, besting Obama’s vote total by 31,090 votes.  

From Sabato:

Republican challenges to Sens. Debbie Stabenow (D-MI), Amy Klobuchar (D-MN), Bob Casey (D-PA), and Tim Kaine (D-VA) are probably longer shots. Trump won Michigan and Pennsylvania last year and came close in Minnesota, but the Senate incumbents in all three states each have won multiple statewide victories and ran ahead of Obama in 2012. Kaine’s vice-presidential campaign, while not making much of a ripple nationally, probably contributed to Clinton running slightly ahead of Obama’s 2012 margin in the Old Dominion. All four Democrats start as clear favorites at Likely Democratic.

Nationally, Sabato has Republicans holding all of their seats up in 2018, and three current Democratic seats listed as tossups.  They are North Dakota, Missouri, and Indiana.