It’s possible Manchin could switch parties. He is a more “moderate” Democrat and when he speaks on Fox News (I’m a regular morning viewer of Fox and Friends) he was never afraid to say what was on his mind - and he wasn’t afraid to admit that he didn’t like Obama.
The mainstream newspapers do cover when Manchin has broken party lines, which has been more often than people think. Manchin voted to defund Planned Parenthood, and he did confirm some of Trump’s cabinet members.
Most of the old “bluedog Democrats” (I liked Zell Miller from Georgia) are unfortunately gone. I remember when James Webb (former Virginia Senator, Vietnam Veteran (forced to retire on a medical) and Defense Secretary under Reagan), one of the last of the Reagan Democrats, was being interviewed by Tucker Carlson. Webb ran for President in the Democratic primary against Clinton, O’Malley, Sanders, and that clown Chaffie. The only interview I remember that was done with James Webb on national media was Tucker Carlson. Tucker asked Webb point blank:
“Senator Webb, why are you still a Democrat?”