From the GOP party platform for 2016 & 2020:
> Our laws and our government’s regulations should recognize marriage as the union of one man and one woman and actively promote married family life as the basis of a stable and prosperous society. For that reason, as explained elsewhere in this platform, we do not accept the Supreme Court’s redefinition of marriage and we urge its reversal, whether through judicial reconsideration or a constitutional amendment returning control over marriage to the states. We oppose government discrimination against businesses or entities which decline to sell items or services to individuals for activities that go against their religious views about such activities.
https://gop.com/platform/renewing-american-values/#Item2
> Traditional marriage and family, based on marriage between one man and one woman, is the foundation for a free society and has for millennia been entrusted with rearing children and instilling cultural values. We condemn the Supreme Court’s ruling in United States v. Windsor, which wrongly removed the ability of Congress to define marriage policy in federal law. We also condemn the Supreme Court’s lawless ruling in Obergefell v. Hodges, which in the words of the late Justice Antonin Scalia, was a “judicial Putsch” — full of “silly extravagances” — that reduced “the disciplined legal reasoning of John Marshall and Joseph Storey to the mystical aphorisms of a fortune cookie.” In Obergefell, five unelected lawyers robbed 320 million Americans of their legitimate constitutional authority to define marriage as the union of one man and one woman. The Court twisted the meaning of the Fourteenth Amendment beyond recognition. To echo Scalia, we dissent. We, therefore, support the appointment of justices and judges who respect the constitutional limits on their power and respect the authority of the states to decide such fundamental social questions.
https://gop.com/platform/we-the-people/#Item4