How would the Senate health care bill actually affect Medicaid?

Democrats and left-leaning think tanks say Senate Republicans’ health care bill would be disastrous for individuals and families on Medicaid, the federal program that provides health coverage to low-income Americans.
But White House press secretary Sean Spicer on Friday said President Trump is “committed to making sure that no one who currently is in the Medicaid program is affected in any way, which is reflected in the Senate bill, and he’s pleased with that.”
So, who is