AUGUSTA, Maine — The national Democratic party’s Senate campaign arm hasn’t endorsed a candidate in Maine’s U.S. Senate race, but it’s wading into the contest with a $410,000 ad buy for a TV spot likely to target Republican candidate Charlie Summers.

The ads from the Democratic Senatorial Campaign Committee will run between Oct. 2 and 12.

“Republican special interests have now spent $2 million boosting a candidate who is fundamentally out of step with the state,” Democratic Senatorial Campaign Committee executive director Guy Cecil said in a statement. “Charlie Summers should not be in the United States Senate, and it is time every Mainer knows it.”

The Democrats’ investment in the Maine Senate race follows nearly $2 million in spending on ads targeting independent former Gov. Angus King, the frontrunner in the race whose lead in the polls has shrunk since early surveys in June. Those ads have come from the National Republican Senatorial Committee, the U.S. Chamber of Commerce and Maine Freedom, a recently formed group whose officers have Republican ties and whose ads have encouraged Democrats to vote for Democratic nominee Cynthia Dill over King.

This is the first investment from national Democrats in the Maine Senate race.

The Democratic Senatorial Campaign Committee, or DSCC, has largely steered clear of the race, endorsing neither King, who hasn’t promised to caucus with Democrats, nor Dill, the Democratic nominee.

“We’re going to continue to monitor the race, but there’s no endorsement in the race,” DSCC spokesman Matt Canter said Friday.

Dill, who has run behind King and Summers in all polls, has criticized the DSCC for not supporting her candidacy.

In an email, Summers spokesman Drew Brandewie said the Democratic ad buy “confirms what we already knew. Charlie’s message of low taxes, less spending and balanced budgets is resonating with Mainers and this race is only going to get tighter.”

National Republican Senatorial Committee spokesman Brian Walsh said in a statement that it’s “remarkable to see national Democrats now spending money in a state where they refuse to even endorse their own nominee.”