Americans not only went to bed not knowing the result of Tuesday’s election, it was also still in doubt when they got up the next morning.

Only around midday local time (6am in eastern Australia) did it become clear that the Democrats had won the Montana senate seat needed to give them control of both houses.

And at 1pm our time, the Associated Press called Virginia. The new AP count showed Democrat Jim Webb with 1,172,538 votes and Allen with 1,165,302, a difference of 7,236. 

While there could still be a recount, and the media are talking up parallels with the 2000 disputed election in Florida, margins that size don’t usually change in real life: there’s a big difference between a few hundred and a few thousand.

That gives the Democrats 49 senators, and with the support of Vermont’s Bernie Sanders and Connecticut’s Joe Lieberman, a 51-49 majority. Lieberman will no doubt be courted by the Republicans, but for now indications are he will be welcomed back into the Democrat fold.

Control of the lower house was never really in doubt; the Republicans must have resigned themselves to losing that weeks ago. But the Senate is the big shift: the effect on Republican morale will be devastating.

And although the Democrats are a long way off being able to override presidential vetoes, Senate control means a greatly increased ability to frustrate the administration’s legislation and appointments.

Democrats also gained six additional governorships – including such major states as New York and Ohio – for a total of 28. That puts them in a stronger position to control important administrative machinery for the 2008 elections and, looking further down the track, the redistributions of seats to follow the 2010 census.

Most polls have cited the Iraq war as the most important single issue in the result, but it is probably the thing that the new Democrat majority can have least direct impact on. Although Congress can threaten to cut off funding for the war (as it did in Vietnam), there is little prospect of it every carrying out such a threat.

The indirect impact, however, will be great, as the demonstrated unpopularity of the administration’s policy has prospective Republican candidates desperately running for cover.