EMILY's List is the latest group to announce it's spending money on the Massachusetts Senate race, which had been billed as a foregone conclusion until last week.

The group announced today it dropped $250,000 on a radio ad in support of Attorney General Martha Coakley (D). The spot is airing statewide, with a concentration in the Boston market, a source said. In a statement, EMILY's List said the 60-second ad “highlights” state Sen. Scott Brown's (R) “record of voting with the Republican leadership 90% of the time and siding with special interests over Massachusetts families.”

That's a popular line of attack against Brown. In the Coakley campaign's first negative TV ad released this week, the announcer calls Brown "a Republican in lockstep with Washington Republicans."