Let's look at the whole of all the facts. Although I'm at work so I gotta make this a hurried response.
Let's look at the tax system that Obama is proposing: if you're making under $250K, you will get a TAX BREAK. If you're making over $250K, your taxes will increase by a graduated amount up to folks making over $1million to have their taxes increasing the most.
Now let's consider Joe the Plumber's situation. He wants to become self-employed, buying the business he's been working for, I presume. The odds of Joe making over $250K, especially the first 10 years or so that he's in business, are EXTREMELY slim. I know this because my husband is in his 7th year of being self-employed owning his own small business. Every year, a lot of his annual taxable income is offset by his business expenses, e.g., buying new equipment, vehicle, computer-related business expenses, etc., etc., causing his total take every year to be far, far below his pre-taxable income. Joe the Plumber's odds of falling above $250K are marginal to none. Therefore, he would actually be paying LESS taxes under Senator Obama's tax plan. Plus I believe that there is something in his plan about payroll taxes decreasing for small-business owners in his plan to handle the recent economic crisis that our country is facing. So, really, Joe the Plumber would be doing pretty well to begin his new business under an Obama presidency.