Lots of people are opposed to the Republicans' plan to replace Obamacare in phases -- Democrats are unified in their opposition, and many Republicans also don't like what Speaker Paul Ryan has put on the table. Everyone who hates it does so for different reasons, but that doesn't mean the plan is a moderate compromise.
I personally don't have a strong opinion on the matter. Ideally, in my opinion, we'd roll back the clock and make it as if Obamacare had never happened, and then use that as our new baseline for future healthcare legislation -- but that doesn't seem to be possible. Given where we are now, it's not obvious that there's a path forward that is both politically feasible and likely to improve our healthcare situation. That stinks.
For the Republican party, it seems likely that the best bet is to do nothing -- wait until Obamacare implodes, and keep their hands clean so they don't get too much blame. It's not at all obvious that letting Obamacare implode is the best path for our country, however.
What a mess.