A state senator from Bangor will be investigated by the state’s ethics commission for her involvement with a political action committee that authorized a $72,919 television ad buy against her opponent.

The Maine Democratic Party filed a complaint with the ethics commission Thursday against Sen. Nichi Farnham, R-Bangor, who is running for re-election in District 32.

The complaint alleges that Farnham, whose campaign receives public funding, has violated a Maine Clean Election Act provision that prohibits Clean Election candidates from coordinating with political action committees.

Documents filed with the commission show that Farnham is the primary fundraiser and authorizing agent for the Maine Senate Republican Majority PAC.

The group, a so-called caucus PAC that is working to re-elect Republican state senators, this week reported the ad purchase against Farnham’s Democratic opponent, Geoffrey Gratwick.

As a Clean Election candidate, Farnham has received $19,955 in public funding.

The Maine Democratic Party has asked the ethics commission to consider disqualifying Farnham from the campaign financing program and assessing civil penalties.

Ben Grant, chairman of the Maine Democratic Party, said the violation is “egregious.”

“Nichi Farnham clearly doesn’t understand the law, or she doesn’t care,” Grant said in a prepared statement.

James Cote, a consultant for the Maine Senate Republican Majority PAC, issued a statement saying that Farnham’s involvement with the group is an “administrative error.”

He said he has documents to prove that Farnham is not involved with the PAC.

“Nichi Farnham has never participated in any discussion regarding independent expenditures from the Maine Senate Republican Majority PAC during this campaign, nor has she ever coordinated any expenditure with that of her own campaign,” Cote said.

The Democrats don’t buy that explanation. The party’s attorney, Kate Knox, said in its complaint to the ethics commission that Farnham is a seasoned lawmaker and that the Republican PAC is too sophisticated to misunderstand the coordination rules.

Farnham is the Senate chairwoman of the Legislature’s Veterans and Legal Affairs Committee, which oversees any changes to the state’s election laws.

“This is one of the largest expenditures ever made at one time in any Maine state Senate race,” Grant said in a release on Thursday. “An ‘awe shucks’ excuse is simply laughable, unless (Farnham) can come up with a definition of ‘primary decision maker’ that I am not familiar with. She can’t now retroactively retire herself from this responsibility.”

The complaint and the size of the ad buy show how much importance both parties see in the District 32 race.

Republican PACs have been sending mailers in the district, as have Democratic-aligned groups.

The Senate Democratic Campaign Committee spent $3,664 in August attacking Farnham in a series of television and online ads that labeled her and four other state senators “rubber-stampers” of Gov. Paul LePage’s agenda.

The TV ads were part of a $19,851 buy by the Democratic PAC.

The same PAC ran mailers against Farnham, but it’s not yet clear how much it has spent for them.

S. Donald Sussman, the majority owner of the Portland Press Herald, Maine Sunday Telegram and other MaineToday Media newspapers, has made significant donations to the Senate Democratic Campaign Committee.

Such political spending isn’t new in Senate District 32.

In 2010, Republican and Democratic groups spent a total of $162,150 trying to influence the race. Farnham defeated Democrat Joseph Perry with 54 percent of the vote.

This year, Democrats, who have more registered voters in the district, think Farnham is vulnerable because she supported many of LePage’s policy initiatives.

This week’s $72,919 TV ad buy is more than any single expenditure from 2010.

Staff Writer Steve Mistler can be contacted at 791-6345 or at:

smistler@pressherald.com

Twitter: stevemistler