A Democratic presidential candidate and two Republicans will stay on the Illinois ballot.
The State Board of Elections dismissed an objection to the candidacy of Democrat Hillary Clinton.
The board ruled Republican U.S. Senators Marco Rubio and Ted Cruz can also stay on the ballot.
Two Illinois residents raised questions about the legality of Cruz and Rubio running for president.
One of the objectors is William Graham of Glen Ellyn. He says the senators are U.S. citizens, but they are not natural-born citizens under the law.