The OPEC oil embargo nearly 40 years was a shock to the U.S. and its economy. But the long-term effects proved a shock to Saudi Arabia and other OPEC members, who learned that oil and politics don't mix. - 

Jeff Horwich: About half of tonight's debate will focus directly on the domestic economy, and you can hardly have that conversation these days without talking about energy policy. To a large extent, our American angst about gas and oil prices dates back to an October event 39 years ago: The OPEC oil embargo. Since then, politicians have pledged never again.

From the Marketplace Sustainability Desk, here's Scott Tong.

Scott Tong: The President has promised:

President Obama: We will finally end our dependence on oil from the Middle East.

Oilman Harold Hamm, an advisor to Mitt Romney, complains,

Harold Hamm: For far too long we stood under OPEC dominance.

In October 1973, the U.S. sent weapons to Israel, during an Arab-Israeli conflict. TV anchors told us that Arab oil producers had cut the U.S. off. Gas prices soared. The U.S. economy fell into recession.

The thing is, it didn't work out for OPEC either, says energy consultant Robin Mills in Dubai.

Robin Mills: They gained a reputation of being unreliable suppliers.

The world started going around OPEC, finding oil elsewhere.

Mills: Whether it's in the Caspian, West Africa, and of course in these days, back in the U.S.

So today, it's OPEC producers like the Saudis are the ones saying 'never again will 1973 come again.'

Industry veteran Mikkal Herberg is now with the National Bureau of Asian Research.

Mikkal Herberg: They are very careful to consistently say, 'oil is a commercial business for us. We do not use it in political ways.

Yet the OPEC bogeyman remains a winning line for American politicians.

In Washington, I'm Scott Tong for Marketplace.

Follow Scott Tong at @tongscott