Two top Republican candidates for governor in Michigan are in danger of being denied a spot on the primary ballot after the state’s election bureau invalidated thousands of signatures submitted by their campaigns, saying many of the names had been forged and were collected by fraudulent petition circulators.The Michigan Bureau of Elections recommended on Monday that James Craig, a former Detroit police chief, and Perry Johnson, a wealthy businessman, be excluded from the Aug. 2 primary, finding that neither candidate met the requirement of submitting signatures from at least 15,000 registered voters.Republicans in the state characterized the move as a politically motivated effort from a Democratic-led agency, while Mr. Craig pointed to his standing in the race.“They want me out,” Mr. Craig said, alluding to Republicans and Democrats. “I’ve been leading.”Three other lesser-known Republican candidates for governor also fell short of the threshold, the bureau determined, meaning that five of the party’s 10 candidates who filed to run for the state’s top office would be ineligible.In its review of the nominating petitions for both candidates, the elections bureau issued a stinging indictment of the methods used by their campaigns to collect signatures and the operatives working for the candidates.“The Bureau is unaware of another election cycle in which this many circulators submitted such a substantial volume of fraudulent petition sheets consisting of invalid signatures,” the bureau said, but clarified that it saw no evidence that the candidates had any knowledge of the fraud.Mr. Craig said in an interview on Tuesday that he would go to court to challenge any effort to deny him access to the ballot.“None of the candidates knew about the fraud,” Mr. Craig said. “Certainly, I didn’t. There needs to be an investigation and prosecution, if, in fact, there is probable cause that they did in fact commit fraud.”While the final say over the candidates’ eligibility rests with the Board of State Canvassers, a separate panel that will meet on Thursday, the recommended disqualification of Mr. Craig and Mr. Johnson threatened to create chaos for Republicans in their quest to challenge Gov. Gretchen Whitmer, a Democrat.Perry Johnson was also widely viewed as one of the top candidates in the state’s Republican primary for governor.Daniel Shular/The Grand Rapids Press, via Associated PressBoth Mr. Craig and Mr. Johnson were widely viewed as front-runners for the party’s nomination in a key battleground state, where Republicans have clashed with Democrats over the legitimacy of the 2020 presidential election and pandemic restrictions.More than half of the 21,305 signatures submitted by Mr. Craig’s campaign were rejected, leaving him with 10,192 valid signatures, the bureau said in its report, which noted that little effort was made to vary handwriting.“In some cases, rather than attempting varying signatures, the circulator would intentionally scrawl illegibly. In other instances, they circulated petition sheets among themselves, each filling out a line,” the bureau said of the petitions for Mr. Craig.Mr. Craig identified Vanguard Field Strategies, an Austin, Texas, firm, as helping to manage the canvassing effort, one that he said relied on several subcontractors that were previously unknown to him. He said that the onus was on the firm to have checks and balances to detect fraud, and he called it “shortsighted” and unrealistic to expect that a busy candidate would verify more than 20,000 signatures.Vanguard Field Strategies confirmed on Tuesday that 18 of the people identified in the elections bureau’s report as circulating the fraudulent petitions had been working for another firm that it had subcontracted to help it gather signatures. The company would not identify the subcontractor, which it characterized in a statement on Tuesday as a nationally respected Republican firm.“The allegations of fraudulent activity, and individuals infiltrating Chief Craig’s campaign in an effort to sabotage it, is very concerning,” Joe J. Williams, Vanguard’s president, said in a statement. “I hope the individuals charged with fraud (none of which worked for or were paid by Vanguard) are held responsible if the allegations are true.”According to Vanguard, Mr. Craig’s campaign retained its services about two months ago, having collected just 500 signatures at the time — the deadline to submit them was April 19.The elections bureau rejected 9,393 of the 23,193 signatures submitted by Mr. Johnson’s campaign, leaving him with 13,800 valid signatures. Some of the fraudulent signatures represented voters who had died or moved out of the state, the bureau said.John Yob, a campaign strategist for Mr. Johnson, did not immediately respond to requests for comment on Tuesday. In a series of tweets on Monday night, Mr. Yob said that the move to disqualify Republican candidates en masse was politically motivated and criticized the head of the state agency that the elections bureau is part of: Jocelyn Benson, a Democrat who is secretary of state.Mr. Yob said that the campaign would contest the bureau’s recommendation.“We strongly believe they are refusing to count thousands of signatures from legitimate voters who signed the petitions and look forward to winning this fight before the Board, and if necessary, in the courts,” he said.On Tuesday, Ron Weiser, the chairman of the Michigan Republican Party, slammed the move to exclude the Republicans from the primary ballot on Twitter.“This is far from over,” Mr. Weiser said. “Democrats claim to be the champions of democracy but are actively angling behind the scenes to disqualify their opponents in an unprecedented way because they want to take away choice from Michigan voters.”Tracy Wimmer, a spokeswoman for Ms. Benson, said in an email on Tuesday night that the election bureau was not swayed by politics.“The Bureau of Elections is staffed by election professionals of integrity who conducted their review of candidate submissions in a nonpartisan manner in accordance with state law,” Ms. Wimmer said.Election officials said that they had identified 36 people who had submitted fraudulent petition sheets consisting entirely of invalid signatures. On Monday, a total of 19 candidates learned that they had not met the signature requirement to get onto the ballot, including three Republicans and one Democrat seeking House seats, and 10 nonpartisan candidates seeking judicial posts.Democrats had separately challenged the petitions of Mr. Craig and Mr. Johnson, but the bureau did not take action because those candidates did not have enough signatures. Mark Brewer, a former chairman of the Michigan Democrats and a lawyer who challenged Mr. Craig’s petitions, defended the steps taken by the elections bureau on Twitter.“What kind of message does it send if any candidate with forged signatures is allowed on the ballot?” Mr. Brewer said on Tuesday. In a 17-page report detailing its findings on Monday, the elections bureau said that the head of one canvassing firm used by the candidates to gather signatures had pleaded guilty to two counts of election fraud in 2011 in Virginia. He was accused of instructing two individuals to sign as a witness on dozens of petition sheets filled with signatures they did not collect, the bureau said.The report did not identify the person, but cited links to news stories and court cases that pointed to Shawn Wilmoth, a political operative based in Michigan, and Mr. Wilmoth’s company, First Choice Contracting LLC.A person who answered the phone at the company on Tuesday said that Mr. Wilmoth was not available, and Mr. Wilmoth did not respond to messages seeking comment.When asked if Mr. Wilmoth or his firm had done work for his campaign, Mr. Craig said on Tuesday that he had learned only that day of a potential nexus.“I don’t want to make excuses,” Mr. Craig said. More