From The Marston Chronicles
It is hard to draw any conclusion from the polls other than that President Obama's approval rating is in free fall.
2010 Generic Congressional Vote
Poll Date Dems Reps Spread RCP Average 6/4 - 7/5 39.7 35.0 Democrats +4.7 Rasmussen Reports 6/29 - 7/5 38 41 Republicans +3 Quinnipiac 6/23 - 6/29 42 34 Democrats +8 Diageo/Hotline 6/4 - 6/7 39 30 Democrats +9
Do you approve or disapprove of the way Barack Obama is handling his job as President?
Poll Date Sample Approve Disapprove Spread RCP Average 6/23 - 7/8 -- 56.5 38.5 +18.0 Gallup 7/6 - 7/8 1547 A 57 36 +21 Rasmussen Reports 7/6 - 7/8 1500 LV 51 48 +3 Quinnipiac 6/23-6/29 3063 RV 57 33 +24 CNN/Opinion Research 6/26-6/28 1026 A 61 37 +24
Perhaps you have noticed that there are wide disparities in these poll results. How can the Presidential approval spread range from as low as 3% to as high as 24%? Do not make the mistake of thinking that this is deliberate on the part of the polling companies. The difference is caused by who is being polled. An "A" after the sample size means that the pollster is asking anyone who is 18 or over who answers the phone the various questions. These least interested people give President Obama an approval rating spread in the low twenties. The "RV" after the sample size tells you that the respondent has to admit that he or she is registered to vote. These people are at least interested enough to register, but now the spread is also in the mid-twenties. Finally we have the "LV" group which is the likely voters which is done by Rasmussen. Notice that the spread is now approaching zero.
Those most interested and most likely to vote have the least support for President Obama. Notice also that only Rasmussen shows the Republicans ahead in the Generic Congressional poll because that is also a likely voter sample. The other factor is the sample size because larger samples have smaller margin of error in the sample selection. So in terms of what the actual people voting are likely to do, look at the "LV" samples.