SEN. JAMIE ELDRIDGE of Acton was a big supporter of his former State House aide, Danillo Sena, when Sena ran for a House seat last year.

According to Sena’s campaign finance report, Eldridge on February 11 personally donated $1,000 to the Sena campaign and Eldridge’s campaign committee donated another $100. Both donations were the maximum allowed under state law.

 On March 24, Eldridge’s campaign committee donated $5,000 to the Massachusetts Democratic State Committee, and a little over a month later the state committee spent $5,950 on a campaign mailing supporting Sena. 

The Eldridge-state committee donation pattern bears a striking resemblance to the donation pattern of Sen. Ryan Fattman of Sutton, whose campaign committee last year donated large sums of money to the state Republican Party and the Sutton Republican Town Committee, both of which in turn made equally large in-kind donations in support of the campaign of Fattman’s wife, Stephanie Fattman, who was running for register of probate in Worcester County. 

In Fattman’s case, the state Office of Campaign and Political Finance determined that the transactions ran afoul of the law and referred them to Attorney General Maura Healey for criminal prosecution. In Eldridge’s case, no referral was made.

 Paul Craney, a spokesman for the Massachusetts Fiscal Alliance and a big supporter of Fattman, believes it’s a case of selective prosecution. He argues that the donations of Fattman and Eldridge were identical in nature and legal – and should be treated the same way.

 The Office of Campaign and Political Finance hasn’t laid out its evidence, but it would appear from what has emerged in public that the office believes Fattman donated to the state Republican Party and the Sutton Republican Town Committee with the understanding that the party and town committee would pass the money along to his wife’s campaign committee. In other words, the arrangement was a way of getting around the $100 limit on donations from one campaign committee to another.

 Eldridge declined to comment on Fattman’s situation or whether he thought his situation and Fattman’s were similar. Eldridge said his campaign committee made the $5,000 donation to the Massachusetts Democratic Party with the hope the party would help Sena but with no assurances that it would.

 “I made the donation, but there was no commitment from the party on how that money would be used,” he said. “In my experience with the Massachusetts Democratic Party, I have found the party extremely focused on following the non-coordination rule.” 

 Fattman has made similar statements.

 The state Democratic Party did go on to provide additional help to Sena’s campaign, spending roughly $1,850 on Facebook ads and $5,922 on another campaign mailing on his behalf. 

 Sena went on to win his race, and Stephanie Fattman was reelected to her position.