Dismissing the liberal arts seems to have become a litmus test for conservative politicians.

Earlier this month, addressing the issue of student debt, Sen. Marco Rubio joked that students ought to know in advance “whether it’s worth borrowing $40,000 to be a Greek philosophy major. Because the market for Greek philosophers is tight.” His remarks echo North Carolina Gov. Pat McCrory, who in 2013 mocked liberal-arts courses and said, “I don’t want to subsidize [a major] that’s not going to get someone a job.” Gov. Rick Scott of Florida and former Gov. Rick Perry of Texas have passed legislation encouraging students to major in STEM (science, technology, engineering and math) disciplines rather than the liberal arts.

This is an unfortunate trend. Conservatives should be among the strongest defenders of the liberal arts, for at least two reasons: one economic, the other philosophical and political.

A recent study by the Georgetown University Center on Education and the Workforce did show that unemployment rates for recent humanities and liberal-arts majors are higher than for, say, biology and life-science students. But the difference is not great: In 2011-12 the rates were 8.4% and 7.4%, respectively. The unemployment rate for recent computer-science, statistics and mathematics graduates was 8.3%. So while humanities and liberal-arts graduates are not making out like bandits, the difference between them and their STEM peers is exaggerated.

Income data provide an even stronger rebuttal to the stereotypes. The National Center for Higher Education Management Systems and the Association of American Colleges and Universities found that humanities and social-sciences majors earn more right after college than students majoring in physical sciences, natural sciences and math. And although they earn less at that stage than peers who major in professional and pre-professional fields, they earn more than those peers by the time they reach the peak earning years of 56-60 years old. (On the other hand, science and math majors earn much more than either group of majors during those peak years.)