The Federal Constitution of 1988 established (art. 163) that it would be up to the Complementary Law to provide for public finances and related topics, in order to impose a greater regulatory density on the matter and denote the need for a more accentuated policy of responsibility in the fiscal management of all federated entities, thus avoiding, as much as possible, possible financial misdeeds, which was due, with considerable delay, to the LC of no 101/2000. In this norm of a complementary-constitutional nature, regulations pertaining to some budgetary types (LDO and LOA) 1, public expenses and revenues, credit operations, public debt and asset management can be seen. Among such legal matters of a financial nature, art. 14 of the LRF disciplines the tax waiver institute, in which the granting or expansion of a tax incentive or benefit from which the waiver of revenue arises, necessarily requires compensation measures. However, the Federal Supreme Court, in ADI No. 5794, decided, in an unprecedented ruling on the subject, that the Fiscal Responsibility Law would not be applied to the so-called labor reform (Law 13.467 / 2017), specifically regarding the contribution portion union destined to the public coffers, thus ratifying one of the biggest tax waivers ever seen in that country, and more serious, without the necessary compensation measures. With this judgment, the counter-majoritarian and representative functions of the STF started to be revised to the detriment of new legal and political perspectives, mainly based on a hearing originated from the vox populi. Minister Luís Roberto Barroso, exponent of this new hermeneutic, advocates for the effectiveness of a new decision category, which he calls “social feeling”, without which he would delegitimize any diffuse or collective decision. However, in a more detailed analysis of these new times, some inconsistencies are noted, such as the unconscious application of utilitarian philosophy, the ideological cradle of a rediscovered liberalism.