Colored by the endless drumbeat of negative news from the MSM, and confronted with relatively high gas prices (though not all that high, historically and accounting for inflation), many Americans really do think the economy, well, sucks. They may have a good job, a nice car, a home, etc, but they are convinced that most other people aren't doing all that well. Although this situtation is manifestly unfair, I still blame Bush for the failure to effectively communicate the truth - on TV, on radio, on the internet - every damned day, if necessary.
I also think the immigration issue has hurt his standing with core Republican voters - and some Democrats as well. No matter: if people really want to see what a bad economy looks like, let them vote Democrat. And, after huge tax increases, when the economy turns to fecal matter, the Dems will of course blame the Republicans, with the Media applauding in unison behind them.
That is because the "traditional" economic metrics measure macroeconomic phenomena, and capture macroeconomic trends.
Individuals, i.e., voters, however, are individuals. And they live within a multiplicity of microeconomies with varying degrees of correlation, or lack thereof, to the macroeconomy.