Dow mid 12,000s, unemployment 4.6 percent, previous quarter GDP 3.5 percent. The Democrats took over Congress.
Democrats and the media will tell you that Bush was entirely responsible for what happened after that, and if that is true, the upcoming election makes no difference. Unless you are terribly happy with unemployment hovering near 10 percent, growth hovering near 1 percent, and the Dow 15 percent below four years ago (more below the high), you may as well "send a message," or stay home.
If Congress makes no difference, Obama will be completely responsible for whatever happens to the economy over the next two years, just as we are told Bush was for '07 and '08. The Democrats told you in '06 that they would deliver "change." Either they just lied because they knew that Congress is powerless, they were clueless, or they were at least partially responsible for what happened since '07. I suspect a lot of truth in the latter two, but in any case, four years is more than enough.