In a decision with profound implications for the role of money in American campaigns, the Supreme Court on Thursday gave interest groups, unions and corporations the right to pour money into issue advertising in political races - reigniting the passionate battle over the influence of cash on the electoral process.

The 5-4 decision punched a hole in the complex web of federal campaign-finance laws and rules in finding that those groups should have the same rights to spend money on political ads as any person. Direct contributions by corporations and unions to individual candidates are still forbidden.

Supporters cheered the ruling, which they said returns the country to the core free-speech precept that political speech should be protected, no matter who or what is speaking.

Critics warned that the foundations of American democracy are at stake and that big businesses will be able to spend enough money to influence elections.