Are tax-exempt bonds for stadiums legal?

The Tax Foundation points to to proposed changes in law by the IRS and Democrats in Congress that would prevent tax exempt bonds from being used for private sports stadiums. 

The changes are aimed at the NY Yankees deal (since everyone hates the Yankees) and the Mets.  I'm not sure how it would affect the Chester soccer stadium deal, but the idea that taxpayers should not be subsidizing the bottom lines of millionaire sports team owners is catching on.