"If you've got Justice Anthony Kennedy on your side, you can pretty much do what you want. Without him, you're the author of an angry dissent," reports The AP's Mark Sherman.
Some fear "huge openings" for foreign corporations to sway elections.
Prof. Nate Persily asks, "What will the Supreme Court's campaign finance ruling really change?"
Possible legislative responses are assessed at SCOTUSblog.
"Money isn't speech, and corporations aren't people," says Prof. David Kairys.
Judging the Environment is collecting scores of op-eds from across the country here.