In July 2017, Gronik announced his candidacy for the Democratic nomination to oppose Scott Walker in the 2018 Wisconsin gubernatorial election. In September 2017, the Milwaukee Journal Sentinel and Associated Press reported that court records were revealed to show that Gronik was fired by his father and sued by his former business partner for allegedly fraudulent business practices. In the same month, it was reported that Gronik was paid at least $6.1 million to settle court cases in which he claimed his move into a mold-infested house negatively impacted his personal health and his family's health. Gronik said toxigenic mold and pathogenic bacteria in the house shocked his Crohn's disease out of remission. It was later reported that Gronik's lawyer falsely claimed that he was terminally ill. On April 19, the Wisconsin Gazette, a statewide LGBT and progressive newspaper, released their endorsement of Andy Gronik stating, "we must ensure the candidate is the one who stands the best chance to win - That candidate is Andy Gronik." In doing so, the Wisconsin Gazette became the first newspaper to formally endorse a candidate in the Democratic Primary of the 2018 Wisconsin gubernatorial election. On May 12, during the Wisconsin Republican Convention, Gronik spent the weekend interviewing Wisconsinites about their experiences with Scott Walker. In addition to these interviews, he sponsored a mobile billboard to circle the convention center that highlighted Walker'sspecial interest takings. During his time outside the convention, Gronik was heckled during his interviews by convention-goers. Gronik submitted 3602 signatures to the Wisconsin Election Commission, well over enough for him to be included on the ballot. The Republican Party submitted a complaint alleging that thousands of these signatures had been collected by felons and were thus ineligible. Gronik responded, stating that while these collectors had committed felonies in the past, they had served their time and were eligible to collect signatures. Further, he stated that in articulating these complaints, the Republican Party was being "offensively racist" by assuming that because the majority of his signatures were from the urban Milwaukee area, that they were felons. The Wisconsin Election Commission reviewed Gronik's signatures, found that they were valid and then struck down the Republican Party's challenge by voting unanimously to place Gronik on the ballot.