The Republican Party has accepted the false premise that Obamacare needs to be replaced.
It doesn't. This is a scare tactic by the Left at getting the Republicans to create a plan similar to Obamacare, so the Dems and media can blame them when that too fails.
The best option right now is to repeal Obamacare completely. Don't worry about the pre-existing coverages, the people who have Obamacare now, etc.