With the campaign season heating up, it is time to take a closer look at a recent U.S. Supreme Court ruling that opens the door for corporations and unions to spend freely and directly on political campaigns.

The ruling, of course, technically applies only to federal races. And we have a doozy of a federal campaign already under way for the seat recently vacated by U.S. Rep. Neil Abercrombie. This opens up a whole new arena of fundraising opportunities for these candidates.

At the local level, Hawai'i has long allowed unions and corporations to participate directly. (An exception, somewhat honored in the breach, is a ban on contributions from contractors actively seeking government work.)

Not a year goes by without someone pushing to stiffen the law. That's going to get tougher now.

The Supreme Court ruling will, if anything, make things even more comfortable for those who like the idea of big business and big labor playing a direct role in the political game.

Depending on how things play out, it could also loosen or even eliminate the modest control the state exerts today over corporate and union contributions: contribution limits.

Donors are restricted to specific amounts, depending on the office being sought and the length of term.

Now, everyone knows that there are ways around any of these rules. Campaign spending reports are replete with examples in which every officer and principal of a particular corporation was somehow inspired to give the maximum amount possible to a particular candidate.

And then there are political action committees ostensibly separate from the interested corporation or union but clearly responsive to their interests.

But still, there are at least minimal controls on the amount of money the big players can give. If the Supreme Court's "free speech" argument plays out locally, forget about any kind of limits.

What that means, of course, is those with the deepest pockets will have even more influence over the political system than they do today.

It is unlikely that anyone will ever come up with a perfect system for regulating campaign contributions and spending.

But there can be improvements. On of the most intriguing suggestions is to create a law that would limit contributions strictly to individuals, and then only from people who live in or have business in the district the candidate hopes to represent.

No foreign contributions. No out-of-state contributions. No contributions from well-heeled downtown players who can spread their influence around the state.

Might be fun. But don't count on it happening any time soon.