Longtime Congressman John Conyers of Michigan doesn't have enough signatures to appear on the Aug. 5 primary ballot, an elections official announced Tuesday.
Conyers' nominating petitions were insufficient, Wayne County Clerk Cathy Garrett said in a statement.
It follows her report last week finding Conyers more than 400 signatures short of 1,000 needed. Garrett said Tuesday that he had 592 valid signatures after challenges.
The 84-year-old Detroit Democrat was at risk because officials believe several people who circulated his petitions do not appear to have been registered voters or had registered too late.
Conyers has three days to appeal Garrett's ruling to the Michigan Secretary of State.
"It is a very unfortunate circumstance that an issue with a circulator of a petition would disqualify the signature of valid registered voter," Garrett said. "However, I am bound by the current laws and statutes of the state of Michigan that set forth very specific and narrow instructions regarding candidate petitions."
Federal court actions, meanwhile, are taking aim at the requirement that petition collectors be registered voters. The ACLU has filed suit to change state law. If neither happens, Conyers can run as a write-in. If he wins the primary as a write-in, he would qualify for the general election ballot.
Detroit Mayor Mike Duggan launched a successful write-in campaign in last year's mayoral primary after his name was not allowed on the ballot due to a residency issue.
In 2012, another Michigan congressman, Republican Thad McCotter of suburban Detroit, didn't make the ballot because a staff member turned in phony signatures or ones from old petitions.
Garrett's ruling will allow Conyers to move forward with his own challenge, said campaign chair state Sen. Bert Johnson.
"Under the U.S. Constitution, every voter who wants to sign a petition to support their desired candidate and political position should be able to do so," Johnson said in a statement. "We look forward to presenting our case before the appropriate authorities.
"There is clear Supreme Court and federal court precedent overturning petition residency laws and requirements, and we are confident that those laws will be invalidated in Michigan as well. As a result, under existing precedent, we believe Representative Conyers will ultimately be placed on the August ballot."
Conyers' opponent in the primary, the Rev. Horace Sheffield III, said Garrett should be commended for her stand.
"I appreciate it — with knowing the relationship and respect she has for the congressman," Sheffield told The Associated Press on Tuesday evening. "I also respect that she did what the law called for her to do."
Sheffield, 59, said his campaign manager, Richard Jones, filed the challenge after learning that at least two people hired to get signatures for Conyers were not registered at the time to vote in Wayne County.
Conyers was elected to the U.S. House in 1964 after winning the Democratic primary by 108 votes.
Since then, he routinely has won re-election — often with more than 80 percent of the vote — and became the senior member of the Congressional Black Caucus, which he helped found.
Conyers was among six black House members when he was first elected, beginning more than 40 years of ballot box dominance over most opponents.
He had represented Michigan's 14th district for decades but moved over to the 13th district in 2012 after Republicans redrew boundaries. At age 83, he still won re-election to a 25th term with 83 percent of the vote.
Conyers got 92 percent of the vote in a 2008 re-election run.
His closest call came in the 2010 general election. That year Conyers received 77 percent of the vote. It came at a time Republicans swept offices across the state, including Rick Snyder's election as governor. The election also came just two months after Conyers' wife reported to prison to begin a three-year sentence for corruption.
The Democratic Congressional Campaign Committee chair issued a statement Tuesday supporting Conyers' re-election bid.
"I have every confidence that when this long process is complete, Rep. Conyers will continue to serve the people of Michigan in Congress," chairman Steve Israel said.