The resignation of Harvard’s president, Claudine Gay, on Tuesday followed a lengthening catalog of plagiarism allegations that appeared to steadily sap her support among the university’s faculty, students and alumni. But for many of Dr. Gay’s critics, her departure was also a proxy victory in the escalating ideological battle over American higher education. Taking down Dr. Gay was a “a huge scalp” in the “fight for civilizational sanity,” Josh Hammer, a conservative talk show host and writer, wrote on the social media platform X.