> Journalists lying to support a narrative is an extremely damaging trend

"Trend" implies a kind of special currency for which I see no evidence; its a "trend" as old as journalism itself. But, yes, its a bad thing.

> that has taken hold on the left

I see no evidence that this is particularly true such that claiming it is a trait of the left, rather than a common feature not especially associated with the left, is anything but a dishonest distortion to support a narrative.

> This of course happens on the right

Indeed.

> but it is not moralized or justified in the same way.

The claim that there is some significant difference here that is worthy of attention desperately could use some support.

   That was in fact a point I was making.

You may have chased a point there but you failed to make it.

In practice almost all such statements (I do not differentiate the style of partisanship) are some combination of disingenuous, lazy, or unintelligent. They are far too broad a brush to be on point, and far too divisive to use unadvisedly. So much so that there is a vanishingly small chance that the addition of such a statement was both necessary to your point, and improves your clarity of argument.

If your intent is intelligent discourse, compelling argument, or even just getting your opinion across clearly then use of this sort of language is actively counter to your purpose. Other aims exist, clearly.

He's saying that your detour into politics is damaging to your narrative.