Cook County Circuit Court will hear testimony Friday on the eligibility of Ted Cruz to run for president. The case is a lawsuit from a voter who alleges that Cruz should not be eligible to run for president because he is not a "natural-born" citizen.

Cruz was born in Calgary, Canada to an American mother before soon after moving to the U.S. That fact has become a major sticking point in the contest for president, one repeatedly raised by Republican front-runner Donald Trump.

Illinois resident Lawrence Joyce will have his case heard in this Chicago-area court.

"My case presents the perfect opportunity for Donald Trump himself to step forward and bring the matter to court personally," Joyce told WBBM radio.

Joyce said he supports Ben Carson for president, however.

Joyce specifically cited his concern about what would happen if Cruz were the nominee. A court case would be highly distracting, and could even imperil the Texan's candidacy.

Rep. Alan Grayson, D-Fla., has pledged to sue if Cruz is the nominee.