Rep. Kevin Cramer won the North Dakota Republican primary for the state’s U.S. Senate seat. He'll face Democratic Sen. Heidi Heitkamp in November.

Why it matters: North Dakota is one of 10 competitive Senate seats Democrats are defending this fall. Heitkamp is vulnerable because she's running for re-election in a state President Trump won by 36 points, but her relationship with the president is worrying Republicans.