If the polls are skewed...

There's been some concern about the accuracy of polls -- are people telling the truth? Is there a skew towards Obama because people are afraid of appearing racist? Is there a skew towards McCain because polls exclude non-land-line owners (who tend to be older and more Republican)?

Well, I can't answer the "accuracy" question with any certainty. However, being the database geek that I am, I can crunch numbers.

I took the poll data from RealClearPolitics and tossed them into an SQLite database; you can download the database itself here. Taking the latest poll data, here's what the election results look like if the percentage points are skewed in one direction or another.

Skew	Obama	McCain	Undecided	Result
McCain +6	263	276	0	McCain
McCain +5	263	215	61	No winner
McCain +4	324	182	33	Obama
McCain +3	357	182	0	Obama
McCain +2	357	182	0	Obama
McCain +1	357	182	0	Obama
No Skew	357	168	14	Obama
Obama +1	371	168	0	Obama
Obama +2	371	168	0	Obama
Obama +3	371	168	0	Obama
Obama +4	371	168	0	Obama
Obama +5	371	158	10	Obama
Obama +6	381	132	26	Obama

In case you want to play with the database:
ELECTORAL_VOTES contains a mapping from state to number of electoral votes for that state (state, votes).
POLLS contains a listing of each poll; the rows contain: state, poll_date, poll_name, obama, mccain.
LATEST_POLLS is a view containing the latest polls from POLLS.
SKEW is a table containing the integers from -6 to 6.

The query to produce the above table is:

select skew, sum(obama_votes), sum(mccain_votes), ifnull(sum(undecided_votes), 0)
  from (select skew, (mccain - obama > skew) * votes mccain_votes,
                     (mccain - obama < skew) * votes obama_votes,
                     (mccain - obama = skew) * votes undecided_votes
         from latest_polls
         cross join skew order by skew) group by skew;