BostonGlobe.com Political Headlines - September 17, 2012

Here are the top POLITICAL headlines from BostonGlobe.com today:

• Romney won't release names of donation bundlers: "Bundlers," people who write big checks and also press their friends and associates to donate to a campaign, make up a whole swath of influential Mitt Romney supporters. Globe business reporter Beth Healy details.  

• Debates loom large in Brown-Warren race: With 51 days to go, the race between Senator Scott Brown and Elizabeth Warren is a true tossup. The sparring sessions are over, and the real battle is finally about to begin. Globe columnist Adrian Walker explains.

• Elizabeth Warren leads Sen. Scott Brown in 2 new polls in US Senate race: Analysts believe that Warren's DNC speech may be responsible for spike in support. Globe politics reporter Noah Bierman and Globe correspondent Matt Rocheleau report.