This will be the first lady's first post-election fundraiser, and is an indication Democrats are taking nothing for granted in the Senate race. A source indicated President Obama is likely to help Markey's campaign with a visit to Massachusetts as well.
Markey will face Republican and local businessman Gabriel Gomez in the general election on June 25, and is heavily favored to win.
But the memory of 2009, when the party lost a Senate seat in a special election due to a bad candidate who ran a weak campaign, remains fresh in the minds of Democrats.
Despite the blue lean of the state and the fact that President Obama won Massachusetts with more than 60 percent of the vote, national Democrats have indicated they'll give Markey any support he may need to cement his chances at a win.
The Globe reports that Massachusetts Democratic Sens. Elizabeth Warren and William “Mo” Cowan are listed as the other two hosts, and the fundraiser requires a minimum contribution of $500.