MSNBC has fired Matthew Dowd, a political analyst whose on-air comments after Charlie Kirk’s death drew criticism, according to a person at the network briefed on the decision. During a back-and-forth with the MSNBC anchor Katy Tur on Wednesday, Mr. Dowd remarked that Mr. Kirk had been pushing hate speech, adding that “hateful thoughts lead to hateful words, which then lead to hateful actions.”