It is yet possible that the Supreme Court will more or less admit in its decision in Obergefell v. Hodges that it is simply making a value-driven policy decision that should have no other precedential effects, but that is not normally how the court works (even in Bush v. Gore, when the Supreme Court attempted to limit the decision to its facts in light of the haste of its decision and its grounding in stopping a runaway state court, the underlying principles took on a life of their own in subsequent election law cases). So the inertial force of litigation will likely make it hard to stop what has been set in motion.
Another obstacle is the Democratic Party. Even as recently as 2006, the Democrats as an institution were interested in persuading culturally moderate voters by appeals to broad-based issues of governance like economics and foreign policy. But the Obama era has thoroughly re-oriented the party around culture war as a tool for motivating young, liberally-inclined voters with little knowledge or interest in other issues.
In the past few years, the declining salience of the Iraq War has elevated LGBT issues to the party’s number one cultural wedge-issue priority (if you don’t believe me, spend a few days reading their fundraising emails). As a result, the Democrats no longer have any incentive to seek anything but constant, zero-sum conflict on these issues. So a Westphalian peace will, if it is to succeed, need to be imposed over the objections of one of the two major political parties. That, too, is an obstacle not easily removed, but like the Obama strategy itself, it will last only so long as it is seen as electorally successful.