President Donald Trump late Friday took one of his first major policy actions by issuing an executive order undoing one of the key pillars of the Affordable Care Act, the individual mandate requiring all Americans to carry health insurance or pay a penalty. The newly sworn-in Trump in the Oval Office signed an order giving federal agencies authority to undo rules created under the ACA that obligate them to enforce the penalty for people who do not purchase health insurance as required by the law, also known as Obamacare.