PORTLAND – Maine’s supreme court overturned a lower court ruling on Monday and said a single faulty signature can invalidate a whole page of a candidate’s nominating petition, effectively removing independent Herbert Hoffman’s name from November’s U.S. Senate ballot.

The Maine Democratic Party, which challenged Hoffman’s petitions, called the ruling a victory for the rule of law. Democrats were concerned that Hoffman, a former Democrat, could have drawn votes away from their party’s nominee, Tom Allen, the 1st District congressman who is attempting to unseat Republican Sen. Susan Collins in a race that is drawing national attention.

Hoffman’s campaign said it was “shocked and surprised” by the decision.

“We have to study it. We don’t know what our next step will be,” said campaign manager Lynn Ellis.

After state Democratic Party chairman John Knutson first challenged Hoffman’s petitions, Maine election officials determined his campaign had collected 38 signatures more than the minimum 4,000 needed for ballot listing.

The Democratic leader then took his challenge to state Superior Court, where it was argued that Hoffman, as a sworn petition circulator, violated his oath because he was not present or aware that three voters had signed one of the petitions. Democrats contended that that lapse should invalidate entire petition sheets on which those names appeared.

Superior Court Justice Donald Marden ruled in favor of Hoffman, saying the secretary of state’s decision not to invalidate the petitions was not an abuse of discretion. Secretary of State Matthew Dunlap said the decision was bolstered by “a whole body of precedent.”

But the Supreme Judicial Court, in Monday’s ruling by five of the seven justices, overruled Marden.

Hoffman attorney John Branson said he had not had a chance to fully digest the 15-page decision, but said it flies in the face of well-established precedent. In similar cases across the nation, he said, the courts give considerable weight to the rights of voters to nominate their choices, but said that issue was given only passing reference in the Maine decision.

He said Monday’s decision was “groundbreaking for this court. It’s the first time the court has ruled you can invalidate an entire petition in the absence of fraud.” Hoffman said the decision “has struck at every voter in Maine.”

Democrats said a decision the other way could have undermined the rules for getting on the ballot and set a dangerous precedent for Maine’s petition-gathering process in the future.

“The sanctity of Maine’s ballot access process was at stake in this case, and today the supreme court did a great service to Maine voters, who can feel confident that all candidates for the U.S. Senate are on the ballot justly,” the party statement said.

Allen’s campaign issued a statement in which it invited Hoffman to join the Democrat’s election effort, saying Allen and Hoffman agree on issues such as withdrawal from Iraq and universal health care.