Obama already did:

I've got to wonder if it will be possible for a plumber to make $250k a year in the US ten years from now.  While Obama was probably right not to do this, he could have gone for the jugular and suggested that this is exactly the sort of job where income depends upon the wages of people in the community.

The greatest economic challenge the US faces during the next ten years might not be recovery from the current recession.  What we might find out when we emerge is that a lot of wealth in the US recently was based upon bubbles which are unrepeatable (just one example, the boost in consumer spending which came from people drawing upon inflated equity in real estate).

It's a cliche that the US has been living beyond its means.  Americans have no recent experience of the sorts of economic events which can cause real income and savings to plummet relatively quickly, though (eg. hyperinflation, massive capital flight, the government not being able to borrow enough to finance its debt).

Not saying these worst-case scenarios are likely.  The truth, though, is that we're heading into unknown territory, and no responsible economist today can say these worst-case scenarios are impossible (indeed, all one has to do is extrapolate from current trends).

So here's the answer I would have given Plumber Joe.  Do you want to go it alone or would you prefer it if we were all in this together?  Because your answer today might not be the one you'll want to give tomorrow.  

What is Joe the Plumber's problem with taxes? If Joe the Plumber (god, I'm hating that phrase) buys additional trucks for his business, he'll need some well-maintained roads to drive them on. I'm sure his business relies on sewage and other water-related infrastructure. Where does he think the money for those kinds of things come from? Without taxes, Joe will be paying more tolls on more roads. Without taxes, local governments will have to charge people (and plumbers) more to access the system. By the way, Joe, tolls are a form of tax. I just don't believe Joe the Plumber (aka McCain operative) understands the purpose of taxes. Finally, with an Obama presidency, taxes will no longer be for enriching the Halliburtons and Exxon-Mobils of this world.

My understanding is that, when Obama says that people who make over $250,000 will see a tax increase,that he is talking about an overall tax increase, not a decrease because of lower rates up to $250,000 and an increase only on income above that figure, which would likely lead to a net decrease.  Otherwise, I am sure he would describe his plan more favorably by raising the $250,000 figure to take account of marginal tax rates.

Did any one hear that this Joe the plumber guy does not make any where near the $250,000 he claims ?

They're interviewing this clown on MSNBC right now. He opposes Social Security (for himself and his retired parents, too).  Prefers to invest his money for retirement in the stock market (he can do that, its called a 401 K) He hates the government, doesn't want anyone "telling him what to do".

He's an immature fool and doesn't represent average Americans.  He does seem to be a Rove plant, why else would the media be covering him so much.