Republican Rep. Devin Nunes accused Twitter in a lawsuit Monday of censoring him and other conservatives during the 2018 elections, as the social media giant admitted it goofed in blocking the content of a conservative commentator last week.

Mr. Nunes, California Republican, argues in his $250 million lawsuit filed in state court in Virginia that Twitter has taken a hands-off approach to scurrilous content directed at conservatives because the company has taken sides, positioning itself as an ally of Democratic politicians and liberal positions on most social issues.