First and foremost, I think the Democrats will take control of the House of Representatives. This is based not on my partisan wishes, but rather the latest polling data (www.pollster.com is the best site and is non-partisan) for competative races - which I obsess over just about every day, as the true political junkie I am. Specifically, I think Dems will pick up about 30 seats (we need 15 to take control) and our majority will be where the Republican is now.
Taking the Senate is a much more difficult feat. Democrats need a net gain of 6 seats and that's about the number of competitive races for Republican seats, so we really have to run the table. Republican incumbents Rick Santorum (Pennsylvania) and Mike DeWine (Ohio) look almost certainly to be defeated at this point, and though to a lesser extent, so do Lincoln Chaffee (Rhode Island) and Conrad Burns (Montana). Thus, the balance of power rests in the outcome of 5 other Senate races. Three are Republican-held (Missouri, Tennessee, and Virginia) and two are Democratic-held (New Jersey and Maryland). New Jersey I think we will definitely hang on to, since though Kean is a great Republican candidate and Menendez has had a lot of problems, Kean simply doesn't have the money at this point to carry him to victory in this very blue state. Furthermore, Menendez has the momentum again. Likewise, in Maryland, despite however good a candidate Steel is, I just don't see this going Republican, especially this year.
As for the Republican-held seats, Democrats are doing as well in these states as only they could in a banner year like this. Harold Ford and Jim Webb are just about the best red states candidates anyone could find and have run great campaigns. The momentum seems to have slid away from Ford in Tennessee in recent days, but Webb is now tied or ahead in Virginia (one thing's for sure, whether he loses or not, Senator George "Macaca" Allen's presidential prospects are over).
This brings us to Missouri which is the tightest Senate race in the country. Democrat Claire McCaskill is running against incumbent Republican Jim Talent. State ballot measures on raising the minimum wage and providing funding for embryonic stem cell research are sure to help Democrats, but Talent still may have a superior get-out-the-vote effort in the remaining days.
So, we need to win two of these three states to get a majority. If we win only one this will make the Senate 50-50 (when you add to the Democratic side Bernie Sanders and likely-winner Joe Lieberman who have promised to caucus with them). Though Cheney gets to cast a tie-breaking vote for majority leader which will put the Senate officially into Republican hands, they will be forced to share power with the Democrats on the committees (Republicans will get the chairmanships, but there will be even amounts of members from both parties) similiar to the agreement Trent Lott and Tom Daschle worked out after the 2000 election.
There will be more competitive races in 2008, so if we don't do so this year, Democrats will have a better chance of capturing Senate control then.
Democrats should also capture a majority of governorships across the country with 5-10 pick-ups (Massachusetts, New York, Ohio, Colorado, Maryland, Minnesota, and possibly Alaska, Idaho, Florida, and Nevada). The number of state legislatures Democrats control should grow as well (as it did even in 2004). We might also gain a majority here for the first time in a decade.
Turning to our own state of Texas, Rick Perry will unfortunately win re-election as governor. Though Chris Bell has solidified support since the debate (he is consistently and solidly second in all recent polls), Grandma and Kinky are still probably splitting the vote too much for him to win. Republicans will likely win the other statewide offices as well, though it'll be interesting to see how well populists David Van Os and Hank Gilbert do. Those two will probably get more votes than any other Democrat in statewide race this year.
Kay Bailey Hutchison will also win re-election, though Barbara Radnofsky will do better than any other Democratic opponent ever has. If she gets 40% she will in decent position to go after John Cornyn, who is more vulnerable than Hutchison, in 2008.
While Texas Dems will probably lose one seat in the State Senate, might get a net gain of 2-5 seats in the State House. The Houston Chronicle suggests that just three new Dems could make it possible for a new Speaker:
Whatever happens, we are in for a truly interesting night tomorrow...