SAT Central Ideas and Details Question

Why do some people with high incomes vote for politicians supporting higher taxes on those with high incomes like themselves? Economists Benjamin Enke et al. propose that values are a luxury good: that is, the higher one's income, the more weight one has the liberty to assign to one's values when voting. Thus, Enke et al. suggest that although the behavior of high-income earners who advocate for higher taxes may seem counterintuitive, such people likely do so because they feel enabled by their economic security to take a stance they think is morally correct. ## Which choice best states the main idea of the text?