MONTGOMERY, Alabama (AP) — To Democrats, Senate candidate Doug Jones' stunning victory in reliably Republican Alabama is more than a quirky one-off. Instead, party leaders cast the upset as a sign of growing nationwide momentum among voters opposed to President Donald Trump and an indication that Democrats shouldn't shy away from competing in Republican territory.

Democrats were bolstered in particular by the higher turnout in Alabama among African-Americans, particularly women; young voters and voters in urban areas, along with a diminished GOP advantage in some small towns and rural areas. T...