competitive district. this one massachusetts congressman bill delahunt. so counting delahunt and massa, democrats now have 17 open seats to defend. republicans have 20. of course, most of those democratic open seats are competitive. most of those republican ones are not. the nbc political unit is rolling out three top ten lists today of house races that we're going to be watching. we have the top ten takeovers, the top ten toss-ups, and then what we're calling the top ten majority makers. this last list is the seats to watch if a tidal wave does hit the democrats, they'll lose a lot of these seats. if it doesn't, they'll hold them and hold their majority. let's look at the top ten takeovers. seven of the ten are democratic seats. most of the races on this list are open seats. one of the exceptions is mary joe kill roy at number ten. till roy nearly lost in 2006 when she lost the first time. eked out a victory in 2008 and now she's getting a rematch with stivers and he's one of the gop's top candidates. in fact, such a big deal is he, he's got an event tonight in