In a nutshell.....They Lied
The lied to their constituents that they could repeal Obamacare. They knew that once the Supreme Court ruled on Obamacare, there was nothing they could do. John Boehner even admitted that it was a done deal
But rather than move on to more important issues (jobs?) they campaigned on repealing Obamacare. They have to make some sort of a token gesture to show they were serious about repealing. So the country has to suffer to cover up for their lie
You have to stop getting your news from Rachel Maddow. There are a lot of Republicans, and maybe you can find a few who actually said this. I don't know, you didn't provide a link. But what most of them said was they would vote to repeal or at least de-fund Obama care. Rachel is to be taken as entertainment value only. She's like Gilligan's Island.