In six years of electoral prognostications, I’ve done pretty well when it comes to calling the final tally in Congress. Over three election cycles, I have called the final composition of the U.S. House of Representatives within 5.3 seats, and the U.S. Senate within 1.7 seats.

I didn’t do as well as I’d have liked last time out. While I correctly foresaw the Republican wave of 2010, I still undercalled the 63-seat GOP pickup by 10 seats, as compared to my average of a 3-seat miss in 2006 and 2008. And I failed to foresee that what the Tea Party did for the GOP in the House would not carry over to the Senate; I overcalled the 6-seat GOP pickup by three seats, compared to my 1-seat misses in 2006 and 2008. It isn’t quite as hard for a radical/fringe candidate to get elected to the House as it is for the same type of candidate to get elected to the Senate, and that is as true for Democrats as it is for Republicans, who left three Senate seats on the table in 2010.

This year, most pundits thought the Republicans would likely capture the Senate, considering they needed only four seats, and the Democrats were defending 23 seats compared to only 10 for the GOP. But again, the Republicans have quite possibly punted away one or two seats by nominating candidates in Indiana (Richard Mourdock) and Missouri (Todd Akin) who have seriously harmed their own chances by espousing unpopular views on abortion in the context of rape-induced pregnancies. At this point, it looks like both are likely to lose, although they are fortunate to be in the states where they are. Both races will probably be close, but the advantage is with the Democrats.

It also turns out that Democrats have nominated a strong crop of Senate candidates, creating competitive races in three states the Republicans were thought certain to win: Arizona, Nebraska and North Dakota. Republicans may still win any or all of those three seats, but they all look to be heading down to the wire.

Finally, expected strong challenges to Democratic Senators in Ohio and Florida have not materialized; Ohio’s Sherrod Brown and Florida’s Bill Nelson, judging by polling trends, should both win reelection comfortably. Two other seats Republicans hoped to take, Virginia and Montana, both look like dogfights. Former Gov. Tim Kaine (D) appears to have a slight lead over former governor and Senator George Allen (R) in Virginia, although weather and electrical conditions could affect early voting, if not election day voting, and potentially alter the result there. In Montana, Sen. Jon Tester (D) is fighting Republican headwinds in his state and will struggle mightily to hold his seat against Congressman Denny Rehberg (R).

To predict the Senate, let’s take a look at the lay of the land. Taking into account the 33 seats that are up for election this year, the Republicans start with a 37-30 edge among the remaining 67 Senators who are not on the ballot until 2014 or 2016.

Among the 33 seats that are on the ballot next week, 13 are considered safe for the Democrats (including the Vermont seat held by independent Bernie Sanders, a self-proclaimed “democratic socialist” who caucuses with the Democrats). Six are considered safe for the Republicans, and in Maine, former Gov. Angus King, an independent, holds a strong lead over his Democratic and GOP challengers. That puts the spread at 43 Democrats, 42 Republicans and 1 independent, with 14 seats up for grabs.

Based on polling trends, it is clear that Democrats have opened clear leads in four of those 13 seats: Florida and Ohio and, belatedly, Massachusetts and Connecticut. Even though those last two are competitive, they seem to be headed into the Democratic column.

While Indiana and Missouri are close, they also appear to be tipping Democratic at this point, which leaves us at 49-43-1 for the Democrats, with seven true toss-ups: Virginia, Wisconsin, North Dakota, Nebraska, Montana, Arizona and Nevada.

Ultimately, it’s guesswork on these seven seats, but now that Wisconsin appears to be tipping back to Barack Obama, I’m going to figure on Wisconsin’s Senate seat going to Democrat Tammy Baldwin. I’m also going to give a slight edge to Kaine in Virginia, and a narrow edge to Rehberg in Montana, though those are both tough calls. In the end, I figure on the Democrats and GOP each taking one of those last two seats.

Democrat Heidi Heitkamp has run a great race in North Dakota, but in the end, I expect she comes up a bit short against Republican Rick Berg, so now I’m at 51-45-1.

In Arizona, Democrat Richard Carmona has consistently held a slight lead over Republican Jeff Flake, and in neighboring Nevada, Democrat Shelley Berkley has consistently trailed GOP Senator Dean Heller by a small margin. I figure on the Republicans and Democrats splitting those two seats as well, though the script could flip. A strong showing by Obama in Nevada could lift Berkley, and negative advertising against Carmona might ultimately sink him. And in Nebraska, former Democratic Senator Bob Kerrey, who was thought to have no chance just a few weeks ago, has been rapidly closing in on Republican Deb Fischer. Kerrey clearly has the momentum and I’m going to call for him to pull out the upset, for a final prediction of: 53 Democrats, 46 Republicans, 1 Independent.

In the House, I have carefully examined the map, and I’ve come to the conclusion there are really only about two dozen seats that are seriously in play. I won’t get into the rundown here, as this post is already long enough, but my call here is a small pickup for Democrats, but not nearly enough to reclaim the Speaker’s gavel. The race starts with a 242-193 advantage for the GOP. I’ve been going back and forth between a final figure of 236-199 and 235-200, but there are a couple unexpected Republican seats that seem like they might go. I’m going to split the difference and call it at 235 Republicans, 200 Democrats.

And that means at least two more years of divided government for whomever is president in 2013. Speaking of which, I’ll have a detailed prediction on the presidential race on Monday.