Apr 16 2019 Former Massachusetts Governor Bill Weld has become the first Republican to challenge Mr Trump in 2020. Former Massachusetts Governor Bill Weld, a fiscally conservative but socially liberal Republican has called Donald Trump a schoolyard bully and said the US president has left the nation in great peril. Bill Weld's announcing his 2020 presidential run on Monday, and they're standing by President Donald Trump, according to a reporter for Business Insider. Any effort to challenge the president's nomination is bound to go absolutely nowhere. the rnc and the republican party are firmly behind the president. Bill Weld officially announces he is challenging President Trump for the GOP nomination.