What percent of Americans are Democrats?

Question

And what percent are Republicans?

Only those two parties, I'm just curious. :]

Answer 1

Greg is probably right about people who claim to be members of each party, however I listened to a lecture given by the former heads of both the DNC and GOP a while back.  Both said they base their campaigns on the knowledge that something like 91% of the population would split evenly between the two parties no matter who the candidates were -- if Joseph Stalin ran against Mother Theresa and one was a democrat and the other a republican, 45.5% of the people would automatically vote for Stalin, and 45.5% for Mother Theresa.  Both leaders were adamant that these numbers were accurate and that they both used them as a basis for campaigning -- they don't consider 91% of the population because they already know how they will vote, so campaigns are targeted at "swinging" 5% or so of the unaffiliated population.

Answer 2

Too many whining Liberals and not enough responsible Republicans.

Answer 3

Though I can't find any recent data, most of the 2006 data says democrats make up roughly 37 % of electorate and republicans 33 %