This sentence, in an article about a speech Don Jr gave to a Trumpian youth group, is itself problematic. It fails to clarify that Don Jr did not intend to be ironic; the irony derives from the weirdness of a speaker who is himself semi-literate attacking another speaker for being semi-literate.
As to what Trump’s lad could have meant by “conform a sentence” — Let Scathing Online Schoolmarm start with this: Poetry is always an option. Poetry can always be deployed politically if people would like to do that, if people think it might be effective. Look at the way Anthony Hecht used not “conform,” but “inform” in this excerpt from a poem about his wife’s miscarriage:
[C]ould it be
That Jewish diligence and Irish jest
The consent of flesh and a midwinter storm
Had reconciled,
Was yet too bold a mixture to inform
A simple child?
If Hecht can twist that word cleverly, can play with connotation and pun (why were we unable to form within her a child; to in-form; to transmit our genetic information…), Don Jr can certainly poeticize “conform” … although SOS is having trouble detecting the connotation/pun/whatever that makes the phrase “conform a sentence” poetically suggestive…
The lad simply means “form,” doesn’t he? What has led him astray is too strong a love for the art of the con.