Immigration policy in the US: What would Jesus do?

Letter to the editor of my local paper on June 6:

Helwig: Who would Jesus allow into America?

The question of what Jesus would do has been asked in connection with illegal immigration. The answer is not complicated. In the Gospel of John, Jesus says, “I tell you the truth, the man who does not enter the sheep pen by the gate, but climbs in by some other way, is a thief and a robber.” Therefore, entering this country illegally is breaking the law as a thief and a robber.

Letter to the editor on June 8 in response to the above:

Kissane: Religion can make bad immigration law

It’s ironic that the writer would place so much importance on strict adherence to immigration laws, while at the same time ignoring a bedrock principle of this country like separation of church and state, by supporting his view of legality with the Bible. If the writer doesn’t want to support fellow human beings simply trying to make their way in the world, he’ll have to be a bit more creative and provide concrete constitutional reasoning for that position. As far as illegal immigration is concerned, a real, workable solution is needed - not vague, religion-based banter.

I accept that we have laws about immigration and they need to followed, or, if they are unjust, revised. But what does Jesus have to do with any of this?