Texas Sen. Ted Cruz says many Americans are concerned that Facebook is biased against conservatives.

Questioning Facebook CEO Mark Zuckerberg at a Senate hearing Tuesday, the Republican senator and former GOP presidential candidate said that to many people there “appears to be a pervasive pattern of political bias” after some conservative pages were taken down from the platform. In a series of pointed questions, Cruz asked Zuckerberg if he had tracked the political affiliations of his employees.

WATCH: Facebook CEO Mark Zuckerberg testifies before Senate committee

Zuckerberg said he had not. But he noted that the company is based in left-leaning Silicon Valley, and said “it is a fair concern.”

Cambridge Analytica, the data-mining firm alleged to have collected private Facebook data on users, has boasted of helping Cruz win the Iowa caucus in 2016.

READ MORE: