Which political party is best for business and the economy?

Bloomberg reports:

While Republicans promote themselves as the friendliest party for Wall Street, stock investors do better when Democrats occupy the White House. From a dollars- and-cents standpoint, it’s not even close...

(O)ver the five decades since John F. Kennedy was inaugurated, $1,000 invested in a hypothetical fund that tracks the Standard & Poor’s 500 Index (SPX) only when Democrats are in the White House would have been worth $10,920 at the close of trading yesterday. That’s more than nine times the dollar return an investor would have realized from following a similar strategy during Republican administrations.