“The environment is right,” said Bill Miller, the Chamber’s senior vice president for political affairs. There will be “a lot more competitive races” this year, and “we have an enthusiastic business community behind us.”

Lisa Goeas, vice president of political affairs for the National Federation of Independent Business, sees a similar phenomenon at her organization, which represents small-business owners.

“Our members are ginned up,” Goeas said. “They’re scared about what they’re seeing. They’re scared about health care. They’re scared about taxes. They’re scared about more regulation. They’re scared about what’s going to happen on the labor front.”

Potter thinks businesses may spend more money on political activities this election, not so much because of the Supreme Court decision, but because they think there’s a good chance for Republicans to pick up seats in the House and Senate and believe “that is worth spending money on.”

Interest groups that support Democrats are likely to increase their political spending as well.

“I have no doubt in my mind that the labor unions will be armed to the teeth,” Miller said.

The biggest impact of the Supreme Court’s ruling will be in the content of the political ads that outside groups run. Business groups and unions now will be able to directly say vote for or vote against a particular candidate. Previously, they could only run what Potter calls “phony issue ads” that highlighted a candidate’s position.

“Being a little more direct will be helpful,” Goeas said, especially “closer to the election.”

Ronald Jacobs—a partner at Venable LLP’s Washington office who develops political compliance programs for corporations, trade associations, and nonprofits—said these groups will no longer “have to try to figure out when issue advocacy becomes candidate advocacy.”

Obama is working with Congress on ways to counteract the Supreme Court’s ruling. Possibilities include legislation to require shareholders to approve corporate spending on political activities. Even without legislation, large shareholders such as pension plans already are pressuring corporations to not spend money on political activities, Jacobs said.