Metaculus has introduced a US Democracy Threat Index. Here is their description:
[It] combines 39 concrete forecast questions into a single metric tracking institutional resilience. These indicators were selected by our returning partners at Bright Line Watch, a nonpartisan group of political scientists from Dartmouth and other leading institutions who have monitored democratic norms since 2017.
Because it’s composed of forecasts, it should change in response to events rather quickly. Here is my more long-term index to monitor if things are going well.
Nehaveigur 