On the campaign trail today, President Obama laid down the clearest challenge yet to the Romney/Ryan approach to tax policy, and left citizens with a challenge question for the other guys:

PRESIDENT OBAMA: Their ideas are pretty simple. They're not hard to explain. They think that if we get rid of more regulations on big corporations and big banks, some of which we put in place to prevent another taxpayer-funded bailout, and if we do more tax cuts for the very wealthiest Americans then somehow prosperity’s going to rain down on all of you. That is their theory.

In fact, the centerpiece of my opponent's entire economic plan is a new five trillion dollar tax cut, a lot of it going to the wealthiest Americans. His new running mate, Congressman Ryan, he put forward a plan that would let Governor Romney pay less than 1 percent in taxes each year. And here's the kicker -- he expects you to pick up the tab.

Governor’s Romney tax plan - this is not my analysis now - this is the analysis of independent folks who analyze tax plans for a living. That’s what they do. Their analysis showed that Governor Romney's tax plan would actually raise taxes on middle class families with children by an average of $2,000. Not to reduce the deficit, not to grow jobs, not to invest in education, but to give another tax cut to folks like him.

Now, ask Governor Romney and his running mate, when they’re here in New Hampshire on Monday - they’re going to be coming here on Monday - ask them if that’s fair. Ask them how it will grow the economy. Ask them how it will strengthen the middle class. They have been trying to sell this trickle-down snake oil before. It did not work then. It will not work now. It’s not a plan to create jobs. It will not reduce the deficit. It will not move the economy forward. It’s the wrong direction for America.

Also? "Trickle-down snake oil" is probably the most visceral metaphor I've heard yet. It made my skin crawl.

I'll be curious to see if anyone takes the challenge.