NEW YORK (Reuters) - The No. 4 Democrat in the U.S. House of Representatives, 10-term incumbent Joseph Crowley, lost his bid for another term on Tuesday to a 28-year-old democratic socialist, Alexandria Ocasio-Cortez.

The stunning upset is the latest sign that the party’s left-wing insurgency is ascendant in 2018. Crowley had not faced a challenger from his own party in 14 years.