How one GOP senator went from saving Obamacare to being OK with undermining it

Senator Lisa Murkowski (R-AK) casted a pivotal vote over the summer, where she — along with Sens. Susan Collins (R-ME) and John McCain (R-AZ) — saved the Affordable Care Act (ACA) from being repealed. She didn’t just vote against repeal once; she voted against three different G.O.P. health bills and shot down another in September.

But on Tuesday, she said she supports legislation that most health experts say will undermine the current health law. In an op-ed in the...