There's been a debate on the left since the January 6th coup attempt: does the conservative movement constitute an autocratic threat against liberalism? Or is that concern being overblown by holders of power to empower the Biden administration and undermine leftist insurgents like Bernie Sanders? After all, the judiciary didn't come close to permitting the coup to go through legally; for an autocratic movement, they don't seem to have much actual purchase.
It seems to me like both views have merit. You might synthesize them by saying that there is a strong anti-democratic tradition in the US, which has flexibly and fluidly moved from using the Constitution and rule of law to defying them.
And not just in that direction! All tools are at its disposal. So Trump really has increased authoritarianism by appointing lackeys with weak fidelity to universal principles and the law, even if when put under the spotlight they sometimes side with the law.
Gerrymandering and steady, whatever-works voter suppression don't make our democratic processeses useless, they just fiddle at the margins and give the GOP more power and the occasional presidency.
Corey Robin, arguing against alarmism about the right, is right that progressives shouldn't see the FBI and CIA as bulwarks against authoritarianism -- they have generally been forces for more authoritarianism. But just as American authoritarianism is fluid and uses whatever it can, so can the forces for American democracy. The FBI and CIA don't have to be only one thing; we can appreciate when they hold the line against political abuse, even if they have happily facilitated political abuse against others.
The Afghan and Iraq wars are a good case to focus on. Our democratic institutions have supported them, and they have been, on balance, a force for authoritarianism, if sometimes in balance with elements of progressivism (girls' education, freer elections).
The 9/11/2001 attacks would have happened if Gore won, but it's reasonable to imagine that the shift toward unaccountable military power and arbitrary violence would have been less severe. We might have not gone to war with Iraq. That win for authoritarianism didn't require a total destruction of democracy, it only required purging Black voters in Ohio and Florida.
There's no chance the GOP will rule forever as a minority party. But just shifting the electoral bias 5% does a lot. Taking one Supreme Court seat does a lot. Running one of history's most successful propaganda media operations does a lot. Coexisting with bonkers conspiracy theories does a lot.
One of the surprising facts about lynching was how effective it was at maintaining rigid racist boundaries, while killing in any one county only occasionally. Lynching never needed to kill everybody, or abolish the rule of law, to succeed. White people were sometimes prosecuted for murdering Black people in the Jim Crow South. Lynching just needed to shift the playing field so that the rule of law was an uphill battle.