Kirstjen Nielsen

President Donald Trump and Homeland Security chief Kirstjen Nielsen never quite clicked personally as the president chafed at her explanations of complicated immigration issues and her inability to bring about massive changes at the U.S.-Mexico border.

The U.S. Department of Homeland Security is creating a center aimed at protecting banks, electric companies and other critical infrastructure against cyberattacks — a threat that now exceeds the danger of a physical attack against the U.S. by a hostile foreign group, Secretary Kirstjen Nielsen said Tuesday.