“We have made ourselves stupid in response to Trump.”

Yes indeed, “crossfire” can be used metaphorically to talk about speech and or debate and/or argument or even at times policies. But I don’t see anyone saying it can’t ever be used that way, so it seems to me to be a strawman argument to act as though they are saying that.

As I wrote earlier, though, if a person uses the word “crossfire” to describe a situation with missiles firing and people dead as a result (as Hennessey used it), then no, it is NOT being used metaphorically. The crossfire of words doesn’t kill people.

That example you gave is not analogous to Hennessey’s used of the word “crossfire.” It would be analogous if those farmers were killed by bullets that Trump had ordered National Guard troops to fire at someone else, and the farmers were standing in the way and got inadvertently hit by stray bullets. In the example you gave, “crossfire” is obviously used in a metaphorical way and there is no firing going on at all and no one is killed – just as, for example, a “trade war” is not a war in the literal sense of bullet and missiles and bombs.

the word crossfire in that phrase implies that both sides were escalating.

No, it doesn’t.

She’s blaming escalation for #PS752, not a literal crossfire.

It’s a bad choice of words, since there was also actual, active fire from one of the belligerents. Now some people refuse to acknowledge the legitimate use of the term as a metaphor.

Definition of cross fire

1a : firing (as in combat) from two or more points so that the lines of fire cross
b : a situation wherein the forces of opposing factions meet, cross, or clash
caught in a political cross fire
2 : rapid or heated exchange of words

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Recent examples on the web:

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As the federal government prepares to roll out $16 billion to help farmers caught in the cross fire of Trump’s trade wars, Democratic congressmen want fishermen included in the deal.

https://www.merriam-webster.com/dictionary/cross%20fire

Does this mean Trump is literally shooting down farmers?

Based on what I saw she was the first out of the gate with it.
But it was obviously a talking point that went out, or something that others latched onto.