Firstly, I intend this thread for discussion of what the title says, namely the chances of the Republicans regaining Congress in the near future. It is not for Democrats to gloat, so lets keep that to a minimum, please.
I think the chances of Republicans gaining ground in Congress during the next two cycles are not very good. There are two trends that work against them: growth and gerrymandering.
Growth. After the 2000 election divided America into red and blue zones, many Republicans delighted in the fact that the fastest-growing parts of the country were all red. Now it’s no longer true. Nevada, the state that’s growing fastest percentage-wise, is now in the Democratic column. So is Florida, the state that’s growing fastest in absolute numbers. So are Colorado, Virginia, and North Carolina, all of which are drawing millions of migrants. And while Georgia and Arizona still tipped to McCain, the prospect of those states turning blue is not as far-fetched as it once was.
Meanwhile, the strongholds for the Republicans in this most recent election are places not experiencing much growth: Arkansas, Oklahoma, Kansas, Nebraska, and the like.
In 2010 there will be a census, and seats in Congress (and electoral votes) will be shifted according to the movement of population. While the blue states in the northeast will lose a fair number of seats, it now seems that blue states elsewhere will pick up most of them.
In short the Republicans ignored one minor detail. When a state experiences rapid growth, people must be coming in from elsewhere. If blue states shrink while red states grow, it’s likely that migrants from the blue states will bring their liberal voting patterns with them.
Gerrymandering. This is when the Congressional districts in a state are divided up so as to favor one party. It happens all the time. In fact, without it the Republicans might have lost their Congressional majority much earlier than 2006. They used gerrymandering to snag six seats in Texas, five in Florida, and three or four in each of Pennsylvania, Ohio, Illinois, Michigan, and Virginia. (Not that the Democrats are blameless either, but the Republicans got more advantages because they controlled more states.)
Now they face two problems. One, the Democrats have gained partial or total power over the state government in most of those states, so we’ll control the redistricting process. Two, it may be possible for President Obama’s Attorney General to simply overrule extreme cases of gerrymandering; it seems to be a legal gray area. The bottom line is that the Republicans will no longer get away with what they used to get away with. As a result, they’ll lose seats.
Here’s an example. Take a look at Congressonal districts in central Illinois. Note the bizarre shape of District 17. It was cut that way to put left-leaing cities together in one single district, which the Democrats always win. Meanwhile, the rest of central Illinois has a slight tilt to the Republicans, allowing them to win Districts 11, 15, 18, and 19. When the map of Illinois is redrawn in a more fair way, all of those districts will become more competitive. This favors the Democrats, since four Republican seats will be at risk.
Now imagine the same thing happening in large states all over the country, and the Republicans losing 10, 15, or more seats from un-gerrymandering alone.
So in toto, combining these trends with changing demographics nationwide, and the picture looks bleak for the Republicans.