Voters can choose to skip contests on their ballot and still cast a valid vote.
Voting for only a single contest, or skipping some contests, is a valid way to vote. Ballots with selections for only certain races happen every election and are counted. This way of voting, sometimes called voter roll-off or “undervoting,” most commonly occurs when voters vote only for the highest office on the ballot and skip “down ballot” races.
In Minnesota for example, unofficial results from the Office of the Minnesota Secretary of State, show 63,178 fewer votes cast for senate than president. In some cases, however, the opposite occurs. In Montana, 1,947 more votes were cast in the senate race than in the presidential race.