In contrast to 2009, the Roman Catholic Diocese of Portland has been relatively quiet in the campaign. Three years ago, the diocese took up collections for opponents of same-sex marriage and loaned a staffer to the campaign. Maine is estimated to be 15 percent Catholic, many of them of French-Canadian origin.

Afterward, some parishioners expressed concern about the diocese’s role — particularly spending thousands of dollars on the campaign when the money was needed elsewhere, said Anne Underwood, cofounder of Catholics for Marriage Equality, which formed in response to the diocese’s 2009 efforts.

This year, the diocese has not loaned out staff, nor has it provided financial assistance to the campaign. Instead, it has held meetings around the state to “teach interested parties about the church’s belief that marriage is defined as the union of one man and one woman,” said David Guthro, a diocese spokesman.

The “church does not seek to impose a law or beliefs on anyone, but instead, to add its voice to the public debate concerning the push to redefine marriage,” Guthro said.

According to campaign finance filings, supporters of same-sex marriage so far have outraised their opponents: Mainers United for Marriage reported raising $3.4 million as of Sept. 30. That includes major contributions from Chris Hughes, a cofounder of Facebook, and his husband, as well as Paul Tagliabue, the former National Football League commissioner.

Protect Marriage Maine has raised $430,000 as of Sept. 30, including $250,000 from the National Organization for Marriage.

The money isn’t needed to persuade Fredrick Jones Sr. The 74-year-old retired ironworker was “put off” when his brother came out years ago. But when his two daughters married women, he changed his mind.