Why do no Republican candidates have any plan to fix healthcare?

I definitely don't like all of the Democratic Candidate's proposals for fixing the problem, but Healthcare definitely is an issue, with people dying because they switch companies after having a pre-existing/uninsurable condition, or after loosing jobs our corporations take to Mexico and India, why do no Republican candidates have any Healthcare Plan on the platforms? Do they think we're too dumb to notice? I might not expect much from someone like Mitt Romney who took his profits to other countries so he could avoid the taxes the rest of us pay, but Giuliani? Paul? I expect something.