SAN ANTONIO (AP) — Assailing President Donald Trump for "a crisis of leadership," former Obama Cabinet member Julian Castro joined the 2020 presidential race Saturday as the rush of Democrats making early moves to challenge the incumbent accelerates.

Castro, who could end up being the only Latino in what is shaping up to be a crowded Democratic field, made immigration a centerpiece of his announcement in his hometown of San Antonio, less than 200 miles from the U.S.-Mexico border.

Two days after the president visited the border to promote his promised wall, Castro mocked Trump for claiming tha...