It looks like there may be a new argument being weather ballooned by the McCain campaign, namely that having the same party in control of both the Legislative and Executive branches of government may not be the best thing for the country. Johnathan Martin at Politico has the details [1]. Of course, the interesting thing is that the premise for this presupposes a poor showing for Republicans in Congress.
Personally, i think this may be McCain’s best argument yet in the pursuit of independents. Just looking over Bush’s term, one can see the validity. I even agree to a point (and have said as much previously), though not enough to change my voting preferences in this election. In 4 or 8 years though, who knows, we’ll have to see what happens.