But renewed ethical concerns about Dixon's official actions could hamper the two-term council president's ability to hold onto the post when she has to campaign for it in the city's 2007 election, political observers say.
Her supporters say Dixon has survived such questions before and that she has plenty of time before the September 2007 Democratic primary to put any ethical worries behind her. Still, political observers said, her opponents will do what they can to make sure voters don't forget.
"I would expect that if she runs for mayor again [in 2007], that whomever her opponents are would trot out her lapses in ethical behavior as fair game," said Donald F. Norris, a professor of public policy at the University of Maryland, Baltimore County.
The city's Board of Ethics is preparing to investigate Dixon's participation in a recent council hearing and three Board of Estimates votes that involved her sister's employer.
The city's ethics law requires public officials to recuse themselves from actions that benefit relatives and to disclose when certain family members, including siblings, work for companies that do business with the city or are regulated by the city.
Dixon never mentioned her sister's job during a council hearing examining whether Comcast of Baltimore had been hiring enough minority contractors -- including the company that employs her sibling, Janice Dixon. The council president formally disclosed the conflict after The Sun revealed it last week. And despite assertions to the contrary, Dixon never abstained from board votes on contracts to her sister's company, Union Technologies.
Supporters believe the conflict was unintentional and that Dixon will survive the latest scrutiny into her actions, as she has before her re-election campaigns in the 2003 Democratic primary and the 2004 general election.
In 2003, The Sun revealed that Janice Dixon worked for the council president's office and that the council was rife with other ethical lapses regarding perks. Dixon easily won the primary election in September 2003. A month later, the ethics board ruled her sister's employment was improper, and Dixon fired her.
The U.S. attorney's office launched an investigation into the council in November 2003 and, as part of the probe, examined Dixon's relationship with a prominent minority developer and gifts she had received from Comcast.
The investigation stalled, however, and Dixon won re-election in 2004 with 84 percent of the vote. A new U.S. attorney discontinued the probe in March 2005.
Dixon's supporters say that if O'Malley becomes governor, she will need to be vigilant about the mere appearance of conflicts.
"Obviously, I think it's going to have some negative effect," said Sen. Nathaniel J. McFadden, the head of Baltimore's Senate delegation. "Obviously, she didn't learn her lesson from the first indiscretion. In her position, she really has to be more careful."
McFadden said he does not believe Dixon "intentionally did anything wrong" and that he is "inclined to give her the benefit of the doubt and let the ethics commission do its investigation."
O'Malley, who ran with Dixon as a "partner in progress" in 2003 and 2004 was not as supportive of the council president as he was during ethical questions in those years.
O'Malley spokeswoman Raquel Guillory said, "The mayor is going to reserve judgment until the ethics board concludes its investigation."
That's in contrast to the defense O'Malley launched in 2003 when he said nepotism was a council tradition and that the ethics board erred in saying the president violated ethics law by hiring her sister. Even as the U.S. attorney investigated the council, O'Malley derided the probe as political.
Some political observers agree that the stakes are much different this time for both O'Malley and Dixon. Some said it's possible that the mayor's opponents could try to use Dixon's behavior to sully his governance.
"I wouldn't be at all surprised if the mayor's opponents run out a whole bunch of negatives about Baltimore City, and this just adds to the list," Norris said.
The campaign of O'Malley's rival for the Democratic nomination for governor, Montgomery County Executive Douglas M. Duncan, declined comment.
Matthew Crenson, a political scientist at the Johns Hopkins University, said Duncan might benefit if he could show that O'Malley was complicit in the Board of Estimates votes that awarded nearly $1 million of work to Dixon's sister's employer. Dixon heads the five-member spending board that O'Malley controls.
Guillory said the mayor did not know of Dixon's sister's job with Union Technologies.
Maryland GOP spokeswoman Audra Miller said she was surprised that O'Malley has not expressed more concern over the matter, especially because he hired an inspector general last year to guarantee the mayor's oft-noted commitment to "open and transparent" government.
"The mayor has been noticeably silent on this issue," Miller said. "The mayor's silence could be construed as approval of these breaking of the ethics laws."
Guillory said the inspector general investigates only the executive branch, not the council.
State Sen. Verna L. Jones said she does not believe Dixon's actions will affect O'Malley except that it will "make them more aware of the transparency needed in all their affairs."
Still, far more observers believe Dixon's questionable actions will be more of an impediment to her political future than to O'Malley's. Her supporters are certain the ethics board will not discover any intentional wrongdoing that will seriously impair her reputation.
"I don't believe she would have done something inappropriate knowing it," Jones said. "If there was some kind of oversight, then that's just what it was."
Del. Salima S. Marriott echoed Jones' support.
"Knowing the president of the City Council like I do, I don't think she would intentionally commit an ethical violation," said Marriott, a Baltimore Democrat. "I know her very well. And I know her to be a very principled person."
Dixon has hired an attorney to represent her as the ethics board probes her actions, and she is not discussing the matter.
While several local leaders said privately that an investigation is warranted, only one would say so publicly.
"The public needs to be confident that elected officials are conducting business in an ethical manner," Del. Jill P. Carter said.
Council members were silent on the matter because Dixon controls council committee appointments and some might be planning to challenge her for either mayor or council president in 2007.
"Almost no one is going to say anything about this," said Carl Stokes, a former council president who challenged Dixon in 2003. "It's not going to come up again from a contender until next summer."
Sun reporter Kelly Brewington contributed to this article.