Obamacare is more popular than ever. Once it was implemented, people began to see the benefits of it such as protection for people with pre-existing conditions.
Now, Trump is lying and saying he will protect people with pre-existing conditions while his Justice Department is supporting an effort to end them.
In addition, Republican candidates are reducing criticism of it:
Trump lies again about pre-existing conditions in his Missouri rally.
Trump lies about pre-existing conditions 10/1/18