Politifact has six ratings: True, Mostly True, Half True, Mostly False, False, and the crowd-pleasing Pants On Fire.
Here is the raw data (counts for each ruling):
NAME True Mostly True Half True Mostly False False Pants on Fire
Obama 80 74 79 42 51 4
Biden 11 11 11 8 6 3
Pelosi 1 2 9 2 3 2
Reid 2 2 3 3 3 1
Boehner 15 3 4 9 16 1
Romney 20 15 19 13 13 8
Perry 15 10 30 22 23 11
Gingrich 3 3 9 6 9 6
There are, of course, problems with this data. I don’t know how Politifact decides which statements to check. The selection process is likely biased in several ways. For example, perhaps controversial or likely-false statements are more likely to become Politifact fodder in the first place. Thus I would be hesitant to conclude that any of the above people are lying X% of the time in general, just because X% of their rulings are False or PantsOnFire. There are a variety of other problems lurking here, especially when the data is thin like for Pelosi and Reid.
Nevertheless, let’s do some math for the fun of it.
In aggregate, 21% of the statements ruled on are TRUE. Boehner is highest at 31% and Pelosi is lowest at 5% (but her data is so thin; one more “true” statement and she would have been 10%). The four Democrats scored 23% in aggregate and the GOP scored 19%.
Expanding to include “mostly true” (and the fully-true), the aggregate is 38%, with Obama best at 47%, and Pelosi and Gingrich bringing up the rear at around 16%. The four Democrats were 44% mostly-true or true, and the GOP was 30%.
False or Pants on Fire is 23% in aggregate. Gingrich is the run away winner here at 42% with Obama the best, of a sorry lot, at 17%. GOP 31%, Democrats 18%.
I also looked at the rulings for the DNC and the RNC. Their numbers:
True Mostly True Half True Mostly False False Pants on Fire
DNC 6 5 8 6 2 0
RNC 2 4 8 5 5 2
This nets out to DNC being Mostly True or True 41% of the time, and the RNC only 23%.
The data is at the very least suggestive that the Republicans, in aggregate, are less truthful than the Democrats though we’d really have to do a more scientific survey (better selection methodology) to draw any real conclusion. Neither party appears to deserve a gold star for veracity.