SARAH BRUMFIELD,Associated Press

BALTIMORE (AP) — A political aide to former Maryland Gov. Robert Ehrlich was convicted Tuesday of conspiring to use Election Day robocalls in what prosecutors cast as an effort to suppress black voter turnout during the 2010 gubernatorial election.

Paul Schurick was found guilty of all four counts he faced, including conspiracy to influence or attempt to influence a voter’s decision whether to go to the polls through the use of fraud and conspiracy to publish campaign material without an authority line. A stoic Schurick comforted his wife in the courtroom after the Baltimore jury’s verdict was read, but declined to comment.

His attorney, A. Dwight Pettit, said they will appeal.

WATCH: Rev. Al on “Politics Nation” discusses Maryland voter suppression case

Visit msnbc.com for breaking news, world news, and news about the economy

Political experts say the case could have an impact on future campaigns, discouraging attempts to keep voters from casting ballots.

Prosecutors argued the calls that went out on the evening of Election Day to about 110,000 voters in Baltimore and Prince George’s County — two jurisdictions with high percentages of black voters — were an effort by the Republican campaign to reduce the number of black Democrats voting in heavily Democratic Maryland.

“Hello. I’m calling to let everybody know that Governor O’Malley and President Obama have been successful,” the call said. “Our goals have been met. The polls were correct, and we took it back. We’re OK. Relax. Everything’s fine. The only thing left is to watch it on TV tonight. Congratulations, and thank you.”

Schurick testified that he rejected campaign consultant Julius Henson’s black voter suppression strategy dubbed “The Schurick Doctrine” but later approved the robocall script. He called it a counterintuitive attempt to mobilize crossover Democrats and said he didn’t know the authority line, which would have noted that the message came from Ehrlich’s campaign, would be left off. Henson, whose trial on similar charges is set to begin in February, has said he did not believe the calls were illegal and that they weren’t meant to suppress the vote.

O’Malley handily won last year’s rematch against the Republican Ehrlich, whom he had unseated in 2006. Ehrlich issued a statement in response to the verdict supporting his friend: “While I vehemently disagree with the decision from a Baltimore City Jury, I do respect our legal system.”

These kinds of activities aren’t new, but have become more problematic recently, said State Prosecutor Emmet C. Davitt. He said he hopes the verdict will send a message that it is more than just “dirty tricks” and the law will be enforced.

“The First Amendment does not protect fraudulent speech,” he said. “We think clearly that this was the case here. It was fraudulent. It wasn’t just political speech.”

The call was fraudulent because the language seemed to come from the point of view of Ehrlich’s opponent and lacked an authority line, he said. He didn’t believe Schurick’s reverse psychology explanation, he said.

“I think it was ridiculous,” he said. “I just don’t buy it and evidently the jury didn’t buy it as well.”

Pettit, the defense attorney, said, “We don’t think the jury understood the issues of law in terms of the First Amendment and constitutional issues. If you allow the state to create arbitrary and capricious laws in terms of vagueness and in terms of what fraud is and allow that kind of prosecution to control free political speech, then you throw a dagger in the heart of our political system.”

Pettit noted that this is the first time someone has been charged under the statute that was revised in 2006 and said his client’s appeal could have an impact beyond this case.

“This has repercussions in terms of state elections, national elections across the board,” he said. “This is a very, very significant constitutional legal issue that has not been decided by the high courts of this nation.”

University of Baltimore associate professor and voting rights expert Gilda Daniels hopes that the verdict does have an impact, showing people that this kind of behavior is wrong.

“Political speech is the highest level of speech, but when you use speech to harm, that’s when you walk outside the protections of the constitution,” she said.

The message was clearly a misrepresentation intended to hold down turnout and ideally the verdict will discourage such behavior, said Donald Norris, director of the Maryland Institute for Policy Analysis and Research at the University of Maryland, Baltimore County.

“This was free speech in the same sense that lying is free speech and lying is not permitted,” he said. “What they were perpetrating was a fraud.”

The First Amendment leaves it to the electoral process to police what are true political ideas or facts, but the government has an interest in making sure people aren’t kept from voting through false statements, ACLU of Maryland staff attorney David Rocah said.

“That’s why we supported and helped pass the legislation that made it a crime to engage in such conduct,” he said. “And we think that the actions that the Ehrlich campaign took in 2010 clearly violated that statute.”

Pettit suggested that the campaign’s Republican political affiliation in a heavily Democratic state influenced the decision to pursue the prosecution.

“This was a political witch hunt from the beginning,” he said.

But Davitt disagreed, noting that the case was opened by his predecessor, who was appointed by Ehrlich.

In addition to the conspiracy charges, Schurick was also convicted of influencing or attempting to influence a voter’s decision on whether to go to the polls through the use of fraud and failing to provide an authority line on distributed campaign material. The authority line violations carry a maximum of a year in prison. The other charges carry up to five years in prison for each count.

Baltimore Circuit Judge Lawrence Fletcher-Hill dismissed an additional conspiracy count and one count of obstruction of justice for allegedly withholding documentation sought through a grand jury subpoena.

A presentencing investigation will be completed before a hearing scheduled for Feb. 16.

Copyright 2011 The Associated Press.