A retired Utah lawyer, Walter Wagner, claims that Cruz does not meet the Constitution's requirement that a president must be a "natural born" citizen. Cruz was born in Canada, and Wager contends that fails the natural born test.
In mid-March, Wagner's case crashed shortly after takeoff for the reason other lawsuits asserting the same claim have failed. He could not meet the test for showing why the candidacy would cause him any particular harm.
Wagner said he had "a vested interest in insuring that all candidates for the position of president are legally qualified." Somebody has to step forward, he said, so it might as well be him.
But federal courts require that those seeking relief must show that they would suffer an injury that's concrete and particular to them. Suing simply on the basis of being a citizen and a taxpayer isn't enough.
"Nowhere does Mr. Wagner allege how he will be injured in a personal and individual way," said US District Court Judge Jill N. Parrish.
Cruz has appealed that ruling, both to the Tenth Circuit Court of Appeals in Denver and the US Supreme Court.
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At least four other lawsuits in federal court, in New Hampshire, Arkansas, Alabama, and Texas, have met similar fates, tossed out on standing grounds.
In late March, the Pennsylvania Supreme Court, in a brief unsigned order, upheld a trial judge's ruling that reached the merits of the issue and found that Cruz met the Constitution's requirement.
A natural-born citizen "includes any person who is a United States citizen from birth," wrote Commonwealth Judge Dan Pellegrini.
Carmon Elliott, the Pittsburgh resident who filed the lawsuit, has vowed to appeal the decision to the U.S. Supreme Court.
This story originally appeared on NBCNews.com.