Republicans are entering the campaign's final stretch poised to sweep back into power in the House of Representatives, with historic gains likely to stem from a broad political strategy that's aligned itself with the national mood.
In the Senate, GOP chances of a takeover appear narrower than they did just weeks ago, although Republicans have put enough Democratic-held seats in play to make a power shift possible there as well.
Republicans have positioned themselves to take advantage of nation-wide voter anger, in part by being just about everywhere in the nation, in both House and Senate races.
There are 431 Republican House candidates on the ballot Tuesday; there are only 435 House districts total. In the Senate, a dozen Democratic-held seats are in play -- more than enough, though with little margin for error, for the GOP to have a shot at the 10 seats the party needs to take power.
Of course, the 100-plus House seats that are in play aren't distributed evenly. They fall into a few major categories that leave Republicans likely to take out some of the old, some of the new and several of the long-since blue.
Start with the new: The biggest chunk of Republican gains are set to come in the same districts that Democrats secured and then padded their majority with over the last two cycles.
Some 55 freshman and sophomore House Democrats are currently in competitive races, according to ABC News' race ratings.
The majority-makers are turning into the majority-breakers, with the vaunted attempts to recruit Democrats that reflect their districts running into the reality that their districts are essentially Republican.
Newer members of Congress have always been among the most vulnerable, since they are less-known political commodities with fewer opportunities to build campaign war chests and exercise real power.
But this is no regular hazing for these underclassmen. Many of them live in what's essentially rented territory for Democrats: A wave of anti-Republican (and anti-Bush) anger swept them in, and another wave is taking them back out in a different direction.
Key races to watch in this category include freshman Rep. Tom Perriello, D-Va., whom President Obama has elevated into the test case for whether you can survive in a red district while supporting the national Democratic agenda; second-term Rep. Christopher Carney, D-Pa., a fiscal conservative locked in a tossup race despite facing a seriously flawed Republican challenger; and freshman Rep. Steve Driehaus, D-Ohio, who's facing a rematch with a former congressman trying to win his old job back.
Then there's the long-since-blue: Democrats have kept a toehold of support in scattered districts across the South, Midwest and the Plains, despite long-term trend lines that favor Republicans.
In many of those districts, veteran Democrats have been able to establish themselves as sufficiently distinct from national leaders. But that's a harder case to make in a nationalized election, with House Speaker Nancy Pelosi's name being used to tar Democrats across the country.
Two open Democratic seats in Tennessee plus one in Alabama appear likely to go Republican, part of what would mark a significant regional realignment in congressional representation.
Add in a crop of incumbents like conservative Rep. Gene Taylor, D-Miss., Rep. Stephanie Herseth Sandlin, D-S.D., Rep. Earl Pomeroy, D-N.D., and 14-term Rep. Rick Boucher, D-Va., and long-time blue spots in red states could wind up all-but erased.
That brings us to the old, as in the old guard of Democrats. These races won't win Republicans the majority so much as they'd fatten it; they wouldn't be the storyline, but they might provide the punctuation marks.
Long-serving Democrats, many of them liberal icons and powerful committee chairmen, are in some of their toughest fights in decades.
Seventeen-term Rep. Ike Skelton, D-Mo., the chairman of the House Armed Services Committee, is among the endangered. So is House Budget Chairman John Spratt, D-S.C., a member of Congress for 28 years, and House Transportation Chairman Jim Oberstar, D-Minn., who's served almost 36 years in the House.
Republicans like their chances against 10-term Rep. Chet Edwards, D-Texas, who counts President Bush among his constituents, plus House Resources Chairman Nick Rahall, D-Va., first elected in 1976.
The GOP is fielding a spirited challenger to House Financial Services Chairman Barney Frank, D-Mass., one of the nation's most prominent liberals -- and whose congressional district supported Sen. Scott Brown, R-Mass., earlier this year.
Even Rep. John Dingell, D-Mich., first sworn in by House Speaker Sam Rayburn and now the longest-serving House member in history, is in a dogfight.
Ultimately, many or most of the veterans could pull off victories. They have survived wave elections in the past, or they wouldn't be where they are now.
But a few wins over big-name Democrats won't just add to GOP numbers -- they'll come to define a brutal election cycle for incumbents across the board.
Meanwhile, in the Senate races, look for the tone of the night to be set early. If Democrats hold on to the Connecticut seat, as expected, a win by Gov. Joe Manchin in the West Virginia race would mean Republicans would have to run the table in every other competitive race to have a shot at control of the Senate.
That includes, of course, Nevada, which is shaping up as the marquee contest of the 2010 cycle. Senate Majority Leader Harry Reid, D-Nev., is the No. 1 target of Republicans and tea party activists, and national tea party energy and money has flowed to Republican Sharron Angle.
Nevada will tell much of the story about what the future of the tea party movement holds -- or could be held up by Democrats as evidence that tea party enthusiasm has real limits in general elections.