You'll know that third party candidates are having an impact when....

.... Al Jazeera starts to cover them.

I'm serious, really. A huge chunk of the world relies on Al Jazeera for coverage of American and international news. Intriguingly, that coverage is usually pretty pedestrian, drawn from the same wire-service reports that small-town US newspapers use (although the editorials are something else).

There is a special page on the American presidential race, whereupon the coverage is usually pro-Obama, except when he's promising to keep Jerusalem for the Israelis at AIPAC. Not surprising.

Months ago, when it seemed that Hillary had a lock on the Democratic nomination and there were still 5 or 6 GOPers in the mix, Al Jazeera did give occasional coverage to Ron Paul, highlighting him as the only candidate actually talking about getting out of Iraq and pursuing a non-interventionist foreign policy.

But since Senator Obama became the presumptive Democrat nominee and Senator McCain secured the GOP nod, there has been no third part coverage at all.

No Ralph Nader. No Bob Barr. Not even an update on Ron Paul.

Why?

My guess is that from the Middle Eastern perspective the American presidential election is chiefly important for foreign policy reasons--getting out of Iraq, de-escalating confrontations with Iran, dealing with Kurds and Turkey or the Pakistani-Indian nuclear stand-off, not universal health care or tax code changes.

Now that there is a major party candidate--Barack Obama--calling for an essentially immediate pull-out from Iraq, he's taken all the air out of the room for third party candidates in terms of Third-World coverage.

Ralph Nader and Bob Barr are not going to be president; so there is going to be minimal interest in them and their now-subsumed calls for Iraqi withdrawal, unless....

It actually appears that third-party candidates are going to draw enough votes in key states to affect the outcome.

If, and only if, Bob Barr shifts the balance of power in Georgia or North Carolina--or Ralph Nader has a similar impact in Michigan or Florida--then we'll start to see international interest in the Libertarians, the Greens, the Constitution Party, etc.

I'll keep you posted. But since most major polling companies in the US are still refusing to include third-party candidates in their preference lists, don't hold your breath.