The mob violence in the U.S. Capitol Building incited by Donald Trump's demagogic speeches has made many people fear that American liberal democracy is crumbling. There are at least four good reasons to believe that is not true.
The first and most fundamental reason is that the progressive expansion of the Lockean Liberal Enlightenment in modern history is too appealing to most human beings to be stopped. The recent wave of illiberal populist demagoguery in the U.S. and elsewhere is only a momentary deviation from the progressive movement towards a deepening liberal political culture. Francis Fukuyama was right--we really have reached "the end of history."
One can see evidence for that even in Trump's political career. He is popular with a minority faction that is large enough to do great harm, as manifest in the social unrest over the past two months. Nevertheless, he has never won a majority of the electorate, and he has suffered a string of three electoral defeats in the 2018 mid-term elections, on November 3, and in the recent George Senate elections.
The second reason to believe that Lockean liberal democracy will prevail in the U.S. is that the American constitutional system has successfully checked Trump's power. As I have indicated in some previous posts (here), Trump's lawsuits for overturning the presidential election have been defeated by the constitutionalism of the judges that Trump himself has appointed. Although Trump has no interest in constitutionalism, he has followed the recommendations of the Federalist Society, which favors a strict constructionist constitutionalism and rule of law that worked against his legal arguments. Moreover, Trump's failure to sway Pence and McConnell towards overturning the election is another triumph for constitutional checks on presidential power.
A third reason for believing that Trump's illiberal populism must fail is that the insurrectionary mob action on Capitol Hill was so shocking that it has provoked a revulsion against Trump and his movement that will simmer for a long time.
Finally, it's clear that the losses suffered by the Republican Party because of Trump--losing control of both Houses of Congress and the White House--will have a sobering effect on the Party. In May of 2016, Lindsey Graham said: "If we nominate Trump, he will destroy our Party, and we will deserve it." Now, many Republican leaders see that he was right.