An administrative law judge found on Friday that Representative Marjorie Taylor Greene should be eligible to run for re-election, saying that he saw no evidence the Georgia Republican engaged in an insurrection on Jan. 6, as several legal challengers had asserted in an effort to have her removed from the ballot.

The ruling by Judge Charles Beaudrot of Georgia’s Administrative Court dealt another setback to a broader campaign by Democrats to hold the staunchest congressional allies of former President Donald J. Trump accountable for the deadly attack on the seat of American democracy last January.

The final say over whether Ms. Greene, 47, who has become one of the most polarizing figures in American politics since she was elected to the House two years ago, can seek re-election will be made by Brad Raffensperger, Georgia’s secretary of state.

A group of constituents from her Northwest Georgia district, backed by a liberal advocacy group, had sought Ms. Greene’s removal from the ballot under the little-known third section of the 14th Amendment, which was adopted during the Reconstruction years to punish members of the Confederacy.

That section declares that “no person shall” hold “any office, civil or military, under the United States, or under any state, who, having previously taken an oath” to “support the Constitution,” had then “engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof.”

But in a 19-page ruling on Friday, Judge Beaudrot said that the legal evidence presented during oral testimony two weeks ago in an Atlanta courtroom and in briefs filed by both sides had left him unconvinced.

“The evidence does not show Rep. Greene engaged in months of planning and plotting to bring about the Invasion and defeat the orderly transfer of power provided for in our Constitution,” Judge Beaudrot wrote.

The ruling suggested that Ms. Greene was not blameless for her rhetoric leading up to the violence at the Capitol. But the judge wrote that there was a difference between a person’s speech and a person’s participation in the attack.

“Her public statements and heated rhetoric may well have contributed to the environment that ultimately led to the Invasion,” Judge Beaudrot wrote.

Ms. Greene’s critics argued that her reference to the gathering of Trump supporters on the National Mall as “our 1776 moment” had been a code word that was used to incite violence. Judge Beaudrot disagreed, writing that he was “unpersuaded” that the comment was a “coded call” for a violent insurrection.

“Heated political rhetoric? Yes,” the judge said. “Encouragement to supporters of efforts to prevent certification of the election of President Biden? Yes. Encouragement to attend the Save America Rally or other rallies and to demonstrate against the certification of the election results? Yes. A call to arms for consummation of a pre-planned violent revolution? No.”

James Bopp Jr., a lawyer for Ms. Greene, said on Friday that he hoped the ruling would put an end to widespread efforts to discredit Republican officials as engaging in an insurrection.

“The Democrat lawyers and their allies who wanted to use First Amendment-protected speech — hyperbole — by Representative Greene to prove that she participated in an insurrection were sternly rebuffed by the judge,” Mr. Bopp said. “That’s good news for the First Amendment and good news for our democracy.”

Free Speech for People, the legal advocacy organization that pursued the case against Ms. Greene, panned the decision and urged Georgia’s secretary of state to defy Judge Beaudrot’s ruling.

“This decision betrays the fundamental purpose of the Fourteenth Amendment’s Insurrectionist Disqualification Clause and gives a pass to political violence as a tool for disrupting and overturning free and fair elections,” the group said in a statement.

A spokesman for Mr. Raffensperger, a Republican who is Georgia’s top elections official, said in an email on Friday that Mr. Raffensperger had received Judge Beaudrot’s ruling and would be reaching a decision soon.

Mr. Raffensperger is facing a primary challenge from Representative Jody Hice, a Republican endorsed by Mr. Trump. The former president has criticized Mr. Raffensperger for rebuffing his attempts to overturn the election results in the state. Georgia holds its primary elections on May 24.