But President Obama's numbers defy that conventional wisdom by staying solid even though the economy is in terrible shape.
Oddly enough he's doing very well with the public even though they're unhappy with the state of the economy. His approval rating is much higher than observers expect it to be based on how the country is actually doing.
The most likely explanation for this is that the majority of Americans still blame George W. Bush for the state of our economy. In fairness Obama hasn't turned it around yet, but it looks like the public didn't expect him to overnight and are intent on letting him win the war and not just the battles.
Gridlock in Congress may be another contributing factor, where's the GOP's rightward march and insuperable opposition to tax cuts and deficit spending are looking more and more extreme to the average voter. Fears over a default have now attached themselves to the Republican party, who - alongside the Tea Party -are now being blamed for the lack of pragmatism that's currently playing out before the cameras.
But it may be something more immediate than Obama's economic policies that's keeping his numbers high. It could simply be the public perception of him as a brilliant if overly cautious political operator who, time after time, meets his targets.
One other contributing possibility, and it bears thinking about, is the quality of the 2012 GOP field.
With several candidates already signing a shockingly extreme (and even racist) pledge to mollify the religious right, whilst others are accused of pandering to their ever changing audiences - the 2012 models barely command the respect of their own base, so it remains to be seen how credible a threat they really pose the president when their candidate of choice is eventually selected.