No, no, I understand what you're saying here, it's just that races are obviously won individually. The generics can only show an overall positive/negative attitude towards the party nationwide, but I'm just not much of a fan of those types of polls. They always tend to be a masturbatory fantasy for 'Rats, since they are more often than not, leading the GOP.
Yeah, it's not a great measure, but they insist on using it. So who am I to fight it? :-)
Most people aren't shallow enough to vote the way their "union" or AARP tells them to. They generally have more than one issue. A terror attack in the states would almost cinch a Repub win in November. The Dems would scream, "You see, we still aren't safe!", but they have no alternative other than to cut and run or negotiate with throat cutters.