Republicans may be pushing to repeal and replace Obamacare. But some states, which operate their own health-insurance exchanges rather than having the federal government do it, are more interested in strengthening the Affordable Care Act than tearing it down.  California, for instance, has become a model for Obamacare. But state exchanges are subsidized by federal dollars and it’s unlikely states will be able to maintain their exchanges on their own if the government pulls the plug.