BISMARCK, N.D. - Republican Kevin Cramer's decision to forgo a Senate campaign in North Dakota is the latest snag for Republicans clinging to a paper-thin majority in the Senate.

The three-term House member says he'll seek another House term despite an hourlong meeting with Trump last week in the White House.

In swing-state Ohio, Josh Mandel's decision to exit the Senate field sets up the chance for a primary between Rep. Jim Renacci and investor and author J.D. Vance.

Ohio and North Dakota are among the 10 states that Trump won in 2016 that have Democrats running for re-election. Republicans hold a 51-to-49 edge in the Senate, a margin narrowed last month by Alabama Democrat Doug Jones' surprise win over Republican Roy Moore a special election.