Bush didn't answer the questi0n.
Since the discussi0n was "live", it d0es say s0mething that W ch0se t0 use the l0aded w0rd "vigilante" in resp0nse. It's clear that by n0t directly answering the questi0n, he's 0ff the h00k by direct qu0tati0n. His th0ughts c0me clearly thr0ugh th0ugh.
It's very likely that W believes in his heart that the MM ARE vigilantes. By his acti0ns, we can c0nclude that W d0esn't really believe that this is a nati0n 0f laws wrt illegal immigrati0n.
0ne is left t0 draw 0nes 0wn c0nclusi0ns, but I think that 6 years 0f inacti0n speaks v0lumes. The vigilante thing is just icing 0n the cake.
You are right, Bush didn't answer the question.
Given that there were no arrests up to that point and given that the President couldn't guarantee that there would be no future vigilante actions, as chief law enforcement officer it would be inappropriate for Bush to answer the question in the following two ways;
(2)Anybody who is at the border now and anybody (including) the Minutemen who will soon be at the border are not vigilantes and will not be vigilantes when they get to the border.
Regarding vigilantism at the border, LE has one task. Arrest and prosecute anybody who has committed a vigilante act.
Since there hadn't been any arrests and since the President can't predict the future, instead of answering the setup question, the President went on to do his job and say what he wanted to see at the border and what he didn't want to see at the border.
BTW, is your keyboard br0ken?