What the Trump administration IS apparently doing with Medicaid, not Medicare, is ending the massively subsidized Obamacare expansion of that that had been scheduled to phase out federal subsidies with states picking up the entire tab. Red states gobbled up this like opium and now they're finding without massive tax increases they can't sustain the expansion. They're upset that Trump, and a Republican congress, won't simply keep forking over the tens, if not hundreds, of billions to support the program.
Most blue states didn't buy into the program and are willing to phase it out. The Democrats, and Left, are playing this as "taking Medicaid away."