“Trump didn’t endorse any of his wives for political office to have them stab him in the back.”
But Trump was disloyal - if it is permissible to use your measuring stick - to his first wives.
I would not say he stabbed them in the back when he changed directions and went for something he liked better. Neither should you throw those terms around because you might end up being repudiated by your own words.
You’re comparing Trump’s married life to his time in office. There’s no comparison. Who in the Republican Party did Trump stab in the back while he was in office? Then give me a list of Republicans who stabbed Trump in the back while he was in office.