WASHINGTON — The Supreme Court's conservative bloc sounded poised Wednesday to strike down on free-speech grounds a 102-year-old ban against corporations spending large amounts of money to elect or defeat congressional and presidential candidates.
If the justices were to issue such a ruling in the next few months, it could reshape American politics, beginning with the congressional campaign in 2010. Big companies and industries -- and possibly unions as well -- could fund campaign ads to support or defeat members of Congress.
For example, the health insurance industry would have a much greater ability to target for defeat lawmakers who supported a so-called public option for medical insurance. Banks and investment firms could oppose representatives who favored stricter regulation of the financial industry.
And far more money could flow into elections. Last year, the political parties spent about $1.5 billion on campaigns, while corporations earned more than $600 billion in profits.
Since 1907, federal law has prohibited corporations from giving money to candidates. And since 1947, corporations and unions have been barred from spending money on their own to urge voters to elect or defeat federal candidates.
Of course, corporate executives, as individuals, can contribute money to a corporate political action committee, or PAC, but these amounts are modest compared with the funds available to corporate treasuries.
At least 24 states (California not among them) have similar bans on corporate spending in state races.
All of those spending limits have come under growing legal attack from conservatives and libertarians who say that the government should not be allowed to set limits on campaign spending and electioneering, even when corporate or union money is in play.
Three justices -- Antonin Scalia, Anthony M. Kennedy and Clarence Thomas -- have already said that they would vote to overrule past decisions that upheld federal and state restrictions on corporate election spending.
Chief Justice John G. Roberts Jr. and Justice Samuel A. Alito Jr. also have said they favor free speech over the campaign funding limits. But they have not yet said whether they would go along and give corporations a free-speech right to spend on campaign ads.
That was the issue before the court Wednesday. It was a rare reargument in the seemingly narrow case of a small nonprofit group called Citizens United.
