"Whether it was his time in Washington as a young priest, his time in the West Indies -- he's seen the effects of what this has done in his priestly ministry," said Donilon.

He stressed that the funds are not coming from parish collection or resources that would normally be diverted to parishes. Instead, these are "unrestricted funds" from the central ministries.

Funds are used for these purposes "rarely," said Donilon, "but when there's such a threat to our social service programs and to our people, then we have to fall on the resources that we have available to us."

He noted the archdiocese has "a track record of this," recalling how it similarly used funds to oppose the Death with Dignity initiative on the 2012 ballot.

The archdiocese's campaign against Question 4 began when Cardinal O'Malley, alongside the other three Massachusetts bishops, issued a statement urging voters to vote against Question 4, Oct. 4.

The call for opposition was heighted two weeks later when Cardinal O'Malley hosted an ecumenical gathering of about 40 faith leaders from around the Boston area, Oct. 18.

The gathering saw representatives of various faith communities discuss their opposition to the initiative, and featured a presentation by Plymouth Republican State Sen. Viriato "Vinny" deMacedo.

Days later, deMacedo also appeared in a short video released online by CatholicTV, in which he presented facts and statistics that highlight the dangers legalization marijuana for recreational use could have on the state.

Cardinal O'Malley was also featured in several similar short videos by CatholicTV.

"As an archdiocese, we are particularly concerned about the serious risks to youth that would follow the enactment of this proposed law," the cardinal said in his blog.

"We educate more than 40,000 students in our schools and have a presence in 144 cities and towns through our 289 parishes. We hold our responsibility for the safety and well-being of children and families as paramount in all that we do."

"Numerous highly credentialed research studies have established the very serious damage to the physical, intellectual and emotional health of youth that is caused by marijuana use. We hold as an important obligation to do all that we can to prevent this from occurring," he continued.