His visit to the state will follow a visit earlier this week by President Obama and one planned for this weekend by former President Bill ClintonBill ClintonSyrian safe zones: Trump's best bet for refugee relief, regional stability Chelsea Clinton attends Muslim solidarity rally in NYC Former Defense chief: Trump's handling of national security 'dysfunctional' MORE, both to stump for Markey.
The Democrat is favored in his race against Republican Gabriel Gomez, and has led in nearly every poll, but Gomez has consistently managed to keep his lead to single digits.
Democrats say they're not concerned about Markey's chances and that the help from big Democratic names — and at least one super PAC, which went on air for the Democrat last week — is simply part of a take-nothing-for-granted strategy.
But the memory of the 2010 special election upset that brought Republican Scott Brown to the Senate looms large in the minds of Massachusetts Democrats, and Gomez has run a solid campaign.
He hasn't yet received much outside help, however, and Democrats have outspent him 3-to-1 on air. One mysterious outside spending group, which bills itself as moderate, announced a $700,000 ad buy for the Republican this week, but there's no indication other groups will follow suit.
Biden to stump for Markey in Massachusetts
By Alexandra Jaffe - 06/14/13 10:25 PM EDT