(Reuters) – Former U.S. Vice President Joe Biden made clear on Monday at his first event as a presidential candidate that he stands ready to battle President Donald Trump for the support of the blue-collar workers who were key to Trump’s election in 2016. Speaking before a welcoming crowd of union workers in Pittsburgh, Biden seemed at times to look past a Democratic nominating contest that promises to be arduous and toward a direct confrontation with Trump in the November 2020 general election.