Propriety for Thee, but Not for Me?

After the Las Vegas shooting, less than a month ago, I began a post thus:

I’ve lost count how many times I’ve written columns, blog posts, or G-Files lamenting the instantaneous politicization of mass murder.

My target at the time (and in countless previous posts in similar circumstances) were all the people desperate to use the fear, anger, and anxiety of the moment to rush through policies they want, namely various gun-control measures.

If a single conservative disagreed with me at the time, I didn’t hear from them.

Well, last night, Donald Trump, not to mention many of my colleagues at Fox and elsewhere, went straight to the issue of the killer’s immigration status. This morning President Trump tweeted, among other things:

But what about conservatives doing exactly what we decry as well? When it’s gun control, we’re all like, “How dare you politicize a tragedy?” This was the White House’s official position in the wake of the Las Vegas shooting. “Now is not the time” etc.

Are we to think that when the blood in the street bolsters the case for even more Extreme Vetting, it’s just fine?

This is an honest question: Is there a meaningful distinction between the two scenarios? Are there some policy questions that are fair in the wake of a terror attack or mass shooting and others that must be held in check pending a respectful mourning period? Or is “propriety for thee, but not for me” the rule now?