[Gianni]

If memory serves they were arrested right after the rebellion. But the passage of the 14th Amendment saved them from trial

So, let me see if I've got this right: Your belief is that a president who was willing to kill 600,000 people to see that the "laws were enforced" had (by your label) criminals come to DC, stay at length, repeatedly petition for a meeting with him, and yet he didn't arrest them?

Doesn't that seem a bit incongruent?

[Non-Sequitur]

So, let me see if I've got this right: Your belief is that a president who was willing to kill 600,000 people to see that the "laws were enforced" had (by your label) criminals come to DC, stay at length, repeatedly petition for a meeting with him, and yet he didn't arrest them?

Not surprisingly you have this wrong. Arrest them on what charge? Talking about rebellion? Advocating rebellion? Supporting rebellion? The envoys were not the leaders of the criminal ring, just the flunkies. Tossing them in jail would have done nothing to alleviate the situation.