A sign on an insurance store advertises Obamacare in San Ysidro, San Diego, California, U.S., October 26, 2017. REUTERS/Mike Blake (Reuters) - A U.S. federal judge in Texas ruled on Friday that the Affordable Care Act, commonly known as Obamacare, is unconstitutional. U.S. District Judge Reed O’Connor in Fort Worth agreed with a coalition of 20 states that a change in tax law last year eliminating a penalty for not having health insurance invalidates the entire Obamacare law.