The campaign to get a marijuana legalization referendum on the Nov. 8 ballot got second life Friday when a Superior Court judge reversed a decision by Secretary of State Matthew Dunlap to invalidate petitions collected by the initiative’s supporters.

The ruling by Justice Michaela Murphy in Business and Consumer Court in Portland came a day after she upheld Dunlap’s determination to invalidate petition signatures in a ballot initiative to put a controversial York County casino question on the November ballot.

David Boyer, campaign manager for the Campaign to Regulate Marijuana Like Alcohol, said Murphy’s ruling in his group’s appeal puts the burden back on Dunlap’s office to go through each petition and check individual signatures against voting records to determine whether they are valid.

“We’re confident voters will be able to vote on this, on taxed marijuana,” Boyer said in a phone interview. “We’re pretty confident. We were confident when we submitted. We were confident when we submitted our appeal. We know they are good signatures.”

Dunlap had raised concerns about variations in the signatures of the notaries who validated the petitions in each of the referendum campaigns.

In rejecting the casino appeal, Murphy noted that even if she overturned Dunlap’s decision on the notaries, the casino proponents still wouldn’t have had enough valid signatures of registered voters. She found the Secretary of State’s Office disqualified many of those signatures for more than one reason, leaving the casino petitioners at least 7,346 voter signatures short of the required 61,123 to reach the ballot.

The Campaign to Regulate Marijuana Like Alcohol disputed the March 2 determination by Dunlap that 26,779 of the signatures it collected were invalid because the signature of the notary who signed the petitions didn’t match the signature on file with his office. Dunlap said that left the campaign with only 51,543 valid signatures. It had turned in 99,229 signatures on Feb. 1.

The campaign focused its appeal largely on the determination that about 17,000 of the 26,779 signatures were invalid for the sole reason that the signatures of notary Stavros Mendros varied and didn’t match what is on file with the secretary of state.

“While the state of Maine has a compelling interest to ensure that all petitions submitted for consideration in a direct initiative are valid, requiring a notary’s signature to appear identically on every petition is unreasonable and abridges the constitutional right to initiative,” Murphy wrote in her 26-page ruling on the marijuana question. “The state has presented no evidence, and the court is aware of none, correlating the variability of a notary’s signature with incidences of fraud in administering the circulator’s oath.”

In the marijuana ruling, Murphy emphasized past rulings by Maine’s Supreme Judicial Court that reserved the people’s constitutional right to ballot initiatives and that those rights must be facilitated by government, not handicapped.

The judge’s ruling will allow the Campaign to Regulate Marijuana Like Alcohol to return to campaigning instead of focusing on the legal dispute, Boyer said.

“We’re definitely excited,” he said. “We’ve been in limbo for the last month.”

Dunlap issued a statement saying, “We thank Justice Murphy for her work and we are reviewing the impact of this decision and considering our options at this time.”

Kristen Muszynski, a spokeswoman for the Secretary of State’s Office, said Dunlap had no further comment beyond his written statement. Dunlap has three business days to file an appeal to the Supreme Judicial Court, she said.

In her ruling, Murphy wrote that Dunlap applied the incorrect and improper standard to invalidate the signatures.

“The secretary of state did not determine that the notaries whose signatures varied from the signatures on their commissions did not properly administer the circulators’ oath. Instead, he claims he was unable to determine whether the notary signatures belonged to those notaries,” Murphy wrote.

Scott Gagnon, director of Smart Approaches to Marijuana Maine, which opposes legalization of marijuana, called Murphy’s ruling “disappointing and unsettling.”

“It will open the door to elections fraud in Maine. We will be watching closely how this unfolds as it goes back to the secretary of state,” Gagnon said in a written statement. “We will certainly be examining all options and strategies for the weeks and months ahead, and we will be prepared should this indeed find its way to the ballot in November.”

The legalization bill would allow adults to possess up to 2½ ounces of marijuana and to cultivate a limited number of plants. Retail stores and social clubs would be allowed with municipal approval. Adults would be prohibited from using marijuana in public, with violations punishable by a $100 fine. The bill also would place a sales tax of 10 percent on retail marijuana and marijuana products.

If Maine were to legalize recreational marijuana, it would join Colorado, Washington, Oregon, Alaska and Washington, D.C., in allowing adults to buy and possess the drug. All have passed laws legalizing recreational marijuana despite a federal prohibition. Legalization proposals are expected to be considered this year in Nevada, California, Arizona, Michigan, Massachusetts and Vermont.