Nothing like lying to your base to reduce the chance of keeping you majority.
Repeal of obamacare was one of the biggest pledges all of the Pubs including Pres. Trump made during the campaign. So far they have failed to keep this promise and the one group , the HFC, that tried to keep this promise was attacked by Pres. Trump, the GOP leadership and the media. Why support a party that attacks it's base and promises to do something for 7 long years and when the opportunity comes to get it done can't do it?