EDINA, Minnesota (CNN) -- Sen. Larry Craig said a Wednesday hearing to overturn his guilty plea stemming from an airport sex sting was "the first major step in the legal effort to clear my name."
"For now, I will continue my work in the United States Senate for Idaho," Craig said in a statement issued by his office in Washington.
A judge in Minnesota heard arguments Wednesday afternoon concerning Craig's June 11 arrest for allegedly making sexual overtures to an undercover male police officer in an airport men's bathroom.
Craig entered a written guilty plea to a disorderly conduct charge in August.
Craig had said he would resign from the Senate if he could not get the guilty plea overturned by September 30. But on Tuesday, Craig said he wouldn't resign until "legal determinations" are made.
In court, Craig's attorneys said the guilty plea lacked a judge's signature and that the evidence did not support the conclusion that a crime occurred.
Defense attorney Billy Martin told the judge, "If [Larry Craig] were to walk in here right now and [the judge] said, 'What did you do?' he could not give you a set of facts that would have constituted an offense for which he could plead guilty."
Martin said he is arguing that Craig did nothing criminal. Looking into a stall to see if it is available or bumping another person's foot is not a crime, he said.
But Hennepin County Judge Charles Porter interrupted Martin and pointed to a line in Craig's guilty plea in which Craig admitted he knew or should have known his behavior would cause alarm.
"If I came storming from around this bench," Porter said, "shaking my fist at you, it might be found by some people in this courtroom to be disorderly conduct."
Prosecutor Chris Renz said Craig, "engaged in a series of invasions of the stall next to him."
The prosecutor cited the police account of Craig's toe-tapping, foot movement and the "repeated stroking of the stall divider with his left hand, each stroke showing more and more of his left hand."
Defense and prosecuting attorneys spoke with reporters outside the courthouse.
"Hopefully we can undo this," the defense attorney said.
Referring to the Idaho Statesman newspaper, which was working on a story about Craig's alleged gay encounters, Martin said his client felt pressure to plead guilty to avoid his arrest coming to light.
"Many of you have read the Statesman [was] doing an article on him and the senator was trying to make this go away, just make it go away," said Martin.
Addressing media, Patrick Hogan of the Metropolitan Airports Commission said Craig pleaded guilty, and "knowingly accepted responsibility and culpability for his actions."
"We anticipate a positive ruling from the court," upholding Craig's guilty plea, Hogan said.
A Republican source involved in discussions about the case said Craig has made it clear he wants to find a way to stay in office.
In his petition to vacate the plea, Craig's attorney maintained the senator's "panic" over the possibility the allegations would be made public drove him to accept a guilty plea without seeking legal advice and that he had been assured by the arresting officer that the matter would remain private.
The petition also claims that because Craig submitted his guilty plea by mail, he did not have the benefit of a judge explaining the exact consequences of the plea before accepting it.
In an affidavit, Renz said the senator was calm and methodical as they discussed his entering a guilty plea and that Craig was warned his case would be a matter of public record.
The document, filed Monday in Hennepin County District Court, also said Renz advised Craig to consult an attorney before entering a written guilty plea -- advice the senator did not take.
Lawyer and media legal analyst Ron Rosenbaum told the Idaho Statesman that Craig's status as a senator works against him in court.
"The guy is a U.S. senator," Rosenbaum told the newspaper. "The judge can assume that he had some knowledge of the legal system and how laws work" when he pleaded guilty.
Meshbesher said Craig had "a good legal argument" because the senator's plea agreement had "no factual basis," meaning the agreement does not spell out specific actions by Craig that violated the law.
But Meshbesher said Porter "has some wiggle room" because the case is so unusual. He said he couldn't recall a withdrawal of a misdemeanor plea in 50 years.
Meshbesher said he thought Porter's ruling would withstand any appeal.
If the judge rules in Craig's favor, his legal troubles might not be over. Prosecutors could file charges again, in which case Craig could "go to trial or plead something else," Meshbesher said.
A Republican source said Wednesday that Craig is telling close associates that if the judge allows his attorneys to reopen the case, Craig plans to stay in the Senate through the trial.
Craig is under intense pressure from GOP leaders and associates in Washington to resign as he first said he would on September 30.
If Craig stays in the Senate, the Ethics Committee has indicated it will investigate his conduct.
A political source said Craig's lawyer was worried the judge would pepper the senator with questions during the hearing. When asked about that Tuesday, Craig said it was not a concern and that he was advised by his attorneys not to appear.
Craig has denied wrongdoing and has said he is not gay. E-mail to a friend
CNN's Dana Bash, Ted Barrett, John King and David Steck contributed to this report.
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