Biden sees path to 270; Trump attacks election integrity

President Donald Trump speaks at the White House, Thursday, Nov. 5, 2020, in Washington. (AP Photo/Evan Vucci)

Democratic presidential candidate former Vice President Joe Biden speaks at the The Queen theater, Thursday, Nov. 5, 2020, in Wilmington, Del. (AP Photo/Carolyn Kaster)

Trump supporter Jake Contos chants during a protest against the election results outside the central counting board at the tcf Center in Detroit, Thursday, Nov. 5, 2020. (AP Photo/David Goldman)

WASHINGTON — President Donald Trump is testing how far he can go in using the trappings of presidential power to undermine confidence in this week’s election against Joe Biden, as the Democrat gained ground Thursday in tight contests in some key battleground states.