Rejection of Commerce Clause "a major blow to Congress's authority to pass social welfare laws"?

http://www.scotusblog.com/cover-it-live/

From SCOTUSblog:


"The rejection of the Commerce Clause and Nec. and Proper Clause should be understood as a major blow to Congress's authority to pass social welfare laws. Using the tax code -- especially in the current political environment -- to promote social welfare is going to be a very chancy proposition."