What is the test for an asylum seeker to prove that they are subject to persecution on the basis of their political opinion?

To establish eligibility for asylum or withholding of removal, an applicant must show persecution, or fear of persecution, on account of race, religion, nationality, membership in a particular social group, or political opinion. See 8 U.S.C. 1101(a)(42); 1231(b)(3). To establish persecution "on account of" political opinion, an asylum applicant must demonstrate that the persecutor's motive arises from the applicant's political belief, "actual or imputed." Castro v. Holder, 597 F.3d 93, 100 (2d Cir. 2010). An applicant "need not demonstrate that a protected ground was the exclusive reason for persecution," and may prevail on a "mixed motive" claim if he demonstrates that his political opinion is "one central reason" for the persecution. Id. at 103-04.