During the joint press conference of 3/17/17 held by President Trump and Chancellor Merkel the President said, in response to a (largely-inaudible) question from Mark Halperin, that
I was in Tennessee--we had a tremendous crowd--the other night. And... they have half the state is uncovered, the insurance companies have left. And the other half has one insurance company and that'll probably be bailing out pretty soon also.
(Q&A starts at about 10:30 in this C-SPAN video)
But Tennessee has a population of over 6M (quoth WP), so that'd be 3M uninsured Americans: a large fraction of the twenty-plus millions of Americans typically quoted as being uninsured. If over 10% of the uninsured come from a state with less than 2% the country's population, that'd be remarkable. But it seems fishy....
Does half of Tennessee not have health insurance in early 2017?