Markos prints a critique of Research 2000’s polling that is stunning. I was reading through it and this is where I knew pretty much all I needed to, though the authors make the case in great detail:

 

Were the results in our little table a fluke? The R2K weekly polls report 778 M-F pairs. For their favorable ratings (Fav), the even-odd property matched 776 times. For unfavorable (Unf)  there were 777 matches.