I guess that's the possible problem with a bigger House. Would it, after the first election, be more competitive? I suppose if there were more Congressmen and they were less exalted and had fewer perks people would feel more inclined to challenge them. Were it to become clear that your one of 1000, 2000, or 3000 Representatives won't bring in any more 'bacon' than any of the others, voting might become more of a referendum on national issues, rather than a rubber stamp for the person who's already been elected. But there does seem to be a lot of single-party sentiment in America, so I wouldn't quite bet on the change making much difference.
As for all the Senate Seats being up for grabs, I'm not so sure. Republican Senators from Massachusetts or Hawaii? Democrats from Mississippi or Wyoming? Still, the nationalization and mediatization of campaigns do make it possible for a Daschle or a McGovern to hold on in what would otherwise be a conservative state.
Yes. With smaller districts where walking to streets and shaking hands would not only be more effective and much less costly than slick TV ads, challengers would have a much better chance.
I have had candidates for State Senate stop me on the street and ask for my vote. Their districts are not much smaller than the congressional districts of an expanded house would be. In most urban areas, they wouldn't cover parts of 4 counties as my district does now. It would be a lot tougher to jerrymander these insane boudries, and on an individual basis, much less expensive to run a campaign.