Enviro group ups spending to unseat Mass. Sen. Brown

The mailer, along with a more than $700,000 canvassing initiative, will likely push the group’s spending on the race over the $1 million mark, Nayak said.

LCV’s political action arm has spent more than $5 million so far in this election cycle, already topping its 2010 total, Nayak said.

It has backed Democrats Warren, Rep. Martin HeinrichMartin HeinrichSenators demand Pentagon action after nude photo scandal Dem senator wants Manafort to testify before Intelligence Committee The one Trump pick leaving greens hopeful MORE (N.M.), former Virginia Gov. Tim KaineTim KaineSenators demand Pentagon action after nude photo scandal RNC drops six-figure ad buy for Supreme Court, healthcare fight Lawmakers want Trump commitment to help Iraq post-ISIS MORE, Rep. Chris MurphyChris MurphyRand Paul roils the Senate with NATO blockade Lawmakers want Trump commitment to help Iraq post-ISIS Ten years later, House Dems reunite and look forward MORE (Conn.) and Sen. Jon TesterJon TesterThe Hill’s Whip List: Where Dems stand on Trump’s Supreme Court nominee Overnight Defense: Pentagon chief urges Congress to approve budget boost | Senate fight over NATO addition Defense chief after Trump tweet: NATO doesn't track 'past money owed' MORE (Mont.).

Last week, LCV opened up a six-figure campaign against Murphy’s Republican opponent, Linda McMahon. The group also spent $850,000 on a direct-mail effort in Virginia that aims to paint Kaine’s rival, former Sen. George Allen (R-Va.), as a pawn of Big Oil.

The group also has spent $1.5 million on House races attempting to unseat five GOP lawmakers it has dubbed the “Flat Earth Five.” That campaign targets Reps. Ann Marie Buerkle (N.Y.), Dan BenishekDan BenishekRepublican groups launch final ad blitz in key House battlegrounds Tea Party class reassesses record Michigan Republican to retire MORE (Mich.), Dan Lungren (Calif.), Quico Canseco (Texas) and Joe Walsh (Ill.).

Nayak said such endeavors would continue through the Nov. 6 election.

“Absolutely,” he said. “We continue to see really stark contrasts between the candidates on our issues in these elections.”

Nayak said he hopes the 150,000 people reached through the mailer will make it “very hard for them to even consider voting for Scott Brown.”

The mailer will emphasize Brown’s vote to sustain oil industry tax breaks, which Nayak said is out of step with most Massachusetts voters.

Nayak noted that a higher turnout is expected in a presidential election year compared with the special election Brown won to replace the late Sen. Ted Kennedy (D-Mass.). He said the mail campaign is necessary to familiarize more of the state’s voters with Brown’s positions and record.

The Hill rates the Massachusetts race as a “toss-up.”