Feb 9 (Reuters) - A former official during the Obama administration was named Tuesday as the new chairman of the U.S. Postal Service Board of Governors as Democratic lawmakers press for changes. Ron Bloom, who has been on the board since 2019, served as a senior Treasury Department overseeing the restructuring of General Motors and Chrysler, was unanimously elected by the board. Service changed made by Postmaster General Louis DeJoy, a supporter of then President Donald Trump, came under harsh criticism for significantly delaying deliveries, prompting DeJoy to suspend operational changes ahead of the 2020 presidential election. (Reporting by David Shepardson)