Reason’s Jacob Sullum discusses.

I am not saying Citizens United had no impact on independent spending. Groups like Karl Rove’s American Crossroads GPS (a 501(c)(4) spinoff of the 527 group American Crossroads) were created especially to take advantage of the freedom allowed by the decision. But its impact on the overall level of independent spending probably was modest in this year’s political environment, which guaranteed that Republicans eager to take control of Congress would spend a lot of money.

That same political environment also meant that spending more money was not the key to victory. Once you consider party and candidate spending as well as spending by independent groups, Democrats outspent Republicans by a substantial margin, for all the good it did them.