Trump must be stopped. NOW. Since he is acting outside the Constitution in organizing an attempted coup, limited actions outside the scope of the Constitution narrowly aimed at restoring the constitutional order, and necessary to secure that end, may be viewed as legitimate.
That means that if Vice-President Michael Pence and the top legislative and military officials determine it is necessary, the authority and powers of the Presidency should be transferred to Pence, and even the arrest and detention of Trump would be justified.
The key point is that the constitutional order has been breached, and even extraordinary measures such as the arrest of Donald Trump would be justified if necessary to re-establish the constitutional order.
A coup d’état is by its very nature a fast-moving event. Those who would defend democracy need to be nimble on their feet and in their thinking, and prepared to act quickly and decisively.