MADISON, Wis. — For more than three years Governor Scott Walker avoided political fallout from a criminal investigation that ensnared six of his former aides and associates, winning a recall election even as his opponent ran ads attacking him on the scandal.
But with the Republican up for reelection this year and considering a run for president in 2016, questions are intensifying over how much he knew about illegal campaign activity going on in his county executive office as he launched his bid for governor.
Democrats are trying to use embarrassing e-mails, which were part of 28,000 pages of documents released Wednesday, to liken his woes to those faced by other embattled Republicans like Governor Chris Christie of New Jersey.
The liberal political action group American Bridge 21st Century, launched a website to coincide with the document release that highlights problematic e-mails and blasts Walker’s role. And Democratic National Committee chairwoman Debbie Wasserman Schultz went after Walker hours after the release, trying to tie Walker’s troubles to Christie’s.
The e-mails are a gold mine for Walker’s opponents, said Democratic consultant Chris Lehane.
‘‘The 28,000 e-mails will allow every reporter, Democrat, and those who have been engaged in a protracted battle with Scott to pick and choose e-mails that they believe will raise questions about the conduct of the office and create what could be countless battles for Scott,’’ Lehane said.
But Walker’s allies say given that Walker was never charged in the investigation, which is now closed, all the attention is much ado about nothing.
‘‘At the end of the day the media’s going to overplay their hand, like they did with Chris Christie, and it’s going to embolden the grass roots to rally around Scott Walker,’’ said Rick Wiley, a former Republican National Committee political director.
The crux of the issue around Walker is far less sexy than the George Washington Bridge lane closures that appeared to be ordered by members of Christie’s administration. The investigation in Wisconsin centered on whether employees in Walker’s county executive office were doing campaign work on the taxpayer dime, which is illegal.
Six former aides and associates of Walker were convicted as a result of the investigation on a variety of charges. His deputy chief of staff, Kelly Rindfleisch, was convicted of misconduct in office, a felony, for doing campaign work for Republican lieutenant governor candidate Brett Davis.
A court transcript of a secret hearing the day before Walker was elected governor in 2010 showed that the lead investigator thought Walker knew about a secret wireless network his aides had installed in the county executive office that they used to do campaign work.
An e-mail from Walker, first made public in 2012, showed him telling staff not to use laptops, visit websites, or take time away during the work day. Walker’s Democratic opponent in the 2012 recall used that e-mail as the basis of an attack ad in that campaign, which Walker won by 7 percentage points.
In another e-mail from 2010 made public Wednesday, an aide welcomed another county worker to the ‘‘inner circle’’ and talked about how she e-mailed Walker and his chief of staff from her private account.
Walker was traveling to Washington for a National Governors Association meeting on Thursday and wasn’t available for comment.