Who do you want to step in to save the capitol from armed right wing protesters? The police and the military are largely sympathetic to the right wing.

The only solution is for the left-wing of US politics to stop disarming itself. The reason that voting power exists is because it represents the fighting power of the voters. When you decouple the two, you create a power imbalance that gangsters and tyrants can exploit.

Capitol riots are just a symptom of that power imbalance.