From a new Pew Research report on Muslim Americans.
http://www.pewforum.org/2017/07/26/terrorism-and-concerns-about-extremism/
The stat is actually worse than the title appears:
11% of Republicans say 'Sometimes' justified, 8% say 'Often'.
Entire report:
U.S. Muslims Concerned About Their Place in Society, but Continue to Believe in the American Dream
Findings from Pew Research Centers 2017 survey of U.S. Muslims
http://www.pewforum.org/2017/07/26/terrorism-and-concerns-about-extremism/
The stat is actually worse than the title appears:
11% of Republicans say 'Sometimes' justified, 8% say 'Often'.
Entire report:
U.S. Muslims Concerned About Their Place in Society, but Continue to Believe in the American Dream
Findings from Pew Research Centers 2017 survey of U.S. Muslims