WASHINGTON (AP) — As Democrat Joe Biden inched closer to the 270 Electoral College votes needed to win the White House, President Donald Trump's campaign put into action the legal strategy the president had signaled for weeks: attacking the integrity of the voting process in states where the result could mean his defeat.

Democrats scoffed at the legal challenges the president's campaign filed Wednesday in Pennsylvania, Michigan and Georgia. In spite of the aggressive move, the flurry of court action did not seem obviously destined to impact the election's outcome.

The new filings, joining exis...