It appears that while Rep. Joe Wilson, R-S. C. was yelling "liar" at President Obama, someone should have been yelling "hypocrite" at him.
Open Congress notes that in 2003 Wilson voted for a plan that used taxpayer money to provide healthcare for illegal aliens:
The vote came on the Medicare Prescription Drug, Improvement and Modernization Act of 2003, which contained Sec. 1011 authorizing $250,000 annually between 2003 and 2008 for government reimbursements to hospitals who provide treatment for uninsured illegal immigrants. The program has been extended through 2009 and there is currently a bipartisan bill in Congress to make it permanent.
Hospitals have a legal obligation to treat everyone who comes in seeking care, regardless of citizenship status, insurance or other characteristics. This means that hospitals treat millions of people every year who don’t have the means to pay. Obviously, this drives up the nation’s healthcare costs overall. Section 1011 helps cushion the costs for hospitals, but it’s not nearly enough to cover the actual costs in most areas.