The U.S. Supreme Court on Monday struck down a law that "triggers" public funding of elections in Arizona in the event of a candidate being heavily outspent by an opponent awash with private funds.

The vote was split 5-4, with the conservative majority ultimately winning out. The ruling declared public financing of candidates to be a violation of free speech.

The decision will have wide-ranging effects across the nation and would significantly alter election law in states where public financing has long been regarded as a means of safeguarding elections from the influence of private sector wealth.