Conservative Washington Post columnist George F. Will has a recent op-ed in which he says that the possibility of divided government is good for John McCain. Since the Second World War, 19 of 31 election cycles have resulted in divided government–one party controlling the presidency and the other controlling the Congress; Americans seem to like this and, as there is little chance that Republicans will control Congress in January, the only chance for divided government is a McCain victory.
Will brings this up again in a more recent editorial, where he points out that over the past 50 years government spending has increased an average of 1.73 percent annually during periods of divided government, but that rate more than triples, to 5.26 percent, for periods of unified government.
Using a similar type of analysis, Slate has a recent article in which they point out that the economy seems to do better under Democratic presidents than under Republican ones–using metrics that conservatives find most important. Looking at the post-1959 economy, they report that Democratic presidents have been better than Republican ones on GDP growth (4.09% vs. 2.94%), inflation (3.81% vs. 4.5%), defense spending (higher under Dems), non-defense spending (lower under Dems), and a better federal budget deficit/surplus situation (-1.21% vs. -2.7%). Only federal taxes (slightly lower under Reps) were more in line with conservative ideals under Republican presidents.
There are too many variables to draw terribly firm conclusions from the data in the Slate article; there isn’t a large enough data set anyway. But it implies that perhaps the ideal situation is a Democratic president and a Republican congress, which is what did occur during six of the eight Clinton years during which the economy did quite well indeed.