Summaries of the Citizens United ruling are available from the Center for Public Integrity, The New York Times and the Connecticut General Assembly, among other sources, as of October 2015. Citizens United ruled that business entities, including unions and corporations, have the same First Amendment free speech rights as individuals.
The Center for Public Integrity summarizes Citizens United by saying that the U.S. Supreme Court sanctioned corporations and labor unions spending whatever amount of money they desired to influence elections. The New York Times reports that the Supreme Court majority vindicated the First Amendment principle barring the government from placing restrictions on political speech. Analysts from the Connecticut General Assembly provide a detailed summary of the Citizens United decision, including its implications for Connecticut and other states.