Trump v Massie: Could president's Republican nemesis survive $20m attack to oust him?
The Fourth Congressional District in Kentucky has become a battleground in the struggle between President Donald Trump and his critics within the Republican Party.
At the center of this fight is Congressman Thomas Massie, who has earned Trump's ire for his willingness to defy the president on key issues. Massie's transgressions against the party line are well documented.