On January 11, 2018, after months of speculation, Cramer announced that he would not seek the Republican nomination for U.S. Senate to run against Democratic-NPL incumbent Heidi Heitkamp and would instead run for reelection to the U.S. House. On February 15, he announced that he had changed his mind and would run for the Senate. Odney advertising firm president Pat Finken served as Cramer's campaign manager. On April 7, Cramer won the North Dakota Republican Party's endorsement. Three days later, his campaign announced it had raised $1.35 million in the first quarter of 2018, most of it in late February and March.