In politics, all the world's a campaign stage, particularly for incumbents. Officeholders enjoy the unique advantage of regularly hitching their names to good works in newspaper and television ads, in government printings, at public events, all in the name of informing the public and all paid for with public dollars.
Think Mayor Thomas M. Menino's name on construction project signs, Secretary of State William F. Galvin's name and picture on voter guides, and Governor Deval Patrick's name on Massachusetts highway signs, among many others.
Now, with the indictment of former state treasurer Timothy P. Cahill on charges of misusing state lottery advertising to benefit his failed 2010 gubernatorial campaign, the question of what constitutes illegal campaigning and what constitutes legitimate promotion for the larger good is up for debate.
Legal specialists say that Cahill's case could prove to be a particularly well-documented line-crossing. Prosecutors allege that e-mails and text messages show there was explicit coordination between Cahill and his campaign in planning ads that promoted the lottery, which Cahill oversaw as treasurer.
In 2010, campaign focus groups found that promotion of the lottery could increase Cahill's chances of winning.
"What Tim Cahill did outwardly is no different than what we've come to expect,'' said Peter Ubertaccio, a professor of American politics at Stonehill College. "It's something every politician does, taking credit for the good stuff that happens in their office.
"What's different in this case is there are e-mails and texts saying [Cahill and his staff] knew full well that this was helping his campaign,'' he said.
Pam Wilmot - executive director of Common Cause Massachusetts, a nonpartisan watchdog group - said, "In this case, there is a smoking gun - the e-mails that tie the advertisement's purpose to a political goal, rather than a public policy goal.''
Cahill's case also stands out because it comes after a lengthy string of Beacon Hill ethics violations that propelled a 2009 change in law, making it a criminal violation for officials to secure privileges not available to members of the general public. Previously, such a case was heard by the Ethics Commission and carried only a fine or other civil penalties.
Now, with a finding of fraudulent intent, a violation can result in both a fine and incarceration.
The indictment represents a first under the new section of the law, said George Brown, a professor at Boston College Law School and former chairman of the State Ethics Commission.
Brown said the Cahill case, while extraordinary for its extensive e-mail trail, reflects the ubiquity of incumbents' instincts for self-promotion, a practice ingrained in candidates for elective office.
"Congress has the franking privilege,'' he said. "They can send free mail to their constituents. They can't send a mailing that says reelect me, but they can send one that says here are all the bills they filed and all the good things they've done.''
Even Attorney General Martha Coakley's decision to undertake this case, he said, could be seen as a politician using her office to generate publicity.
"One could say, if one wanted to be perverse, that Attorney General Coakley was taking advantage of her office by holding a press conference to announce an anticorruption investigation that would be a benefit to her,'' he said.
Brown said he was making no accusation but illustrating a broader point. "It's very hard to disentangle the advantages of incumbency and separate what is proper and improper,'' he said.
Brad Puffer, a spokesman for Martha Coakley, declined to discuss the case in detail beyond what has already been made publicly available.
But he said, "There are major differences between the use of materials to educate the public and the unlawful behavior we allege in this case.''
Warren E. Tolman, a former gubernatorial candidate, said the Cahill case is likely to have political reverberations.
"When you're buying an ad campaign like this, obviously you are going to have to be wary,'' he said.
Tolman said fixing the laws to gain greater clarity in the division between the legal promotion of good works and illegal self-promotion would be nearly impossible for the Legislature.
Mandating, say, that a politician's name and face not appear in the ad would do little good, he said, noting that Cahill's face and name appeared nowhere on the lottery ads in his case.
"That's the hard part of it,'' he said. "Where do you draw the line?''
Brown said the surest way for politicians to stay safe as they plan advertising strategy, might be to follow an old adage: "Don't write it if you can speak. Don't speak it if you can nod. Don't nod if you can blink.''
Sarah Schweitzer can be reached at email@example.com.