The Fourteenth Amendment is one of the hardest provisions in the Constitution to get right. Sometimes there seem be as many theories of the provision as there are theorists. I admire their persistence. While I am not an expert in the all the intricacies of the Amendment myself, I do think it very probable that it protects economic liberty at least from discriminatory and arbitrary interference. Thus, its original meaning offers support for recent courts that have invalidated irrational licensing schemes.
For me, three reasons combine to present a persuasive case that the Fourteenth Amendment protects economic liberty. First, there seems little doubt that the Fourteenth Amendment was ratified in part to permit federal protection of economic rights. Before ratification, there had been constitutional doubts about the Civil Rights of 1866 which was aimed at preventing discrimination against African Americans in their exercise of economic rights like the right to contract. That background suggests that either the Privileges or Immunities Clause, or the Due Process Clause, neither of which by their terms are limited to racial discrimination, must cover economic rights. (For reasons elaborated by Chris Green and John Harrison, I tend to think that the historical meaning of equal protection did not provide a general basis for preventing discrimination in the decision about what laws to adopt).
Second, this interpretation of the Fourteenth Amendment also makes it comport with an important part of the ideology of Republican party—free labor. Thus, understanding the Fourteenth Amendment as protecting economic liberty also has the advantage of making it flow from the central tenets of the political party that was responsible for entrenching that clause in the Constitution. These first two reasons are particularly powerful in combination: the inclusion of economics liberties within the Amendment’s scope gives it an expected legal effect that would also have resonated with popular popular political commitments.