Well, the "Law and order" part applies to OTHER PEOPLE. Republicans get special pleading to lower the bar for them(In particular Trump, who apparently should be held to the lowest possible standard if any standard at all). It's pretty pathetic but that's what it is.
Trump's main supporter base are right-wing authoritarians.
Right-wing authoritarians are strong believers in law, order, and submission to authority. However, there's a big kicker in there: that's the law, order and authority
that they perceive as morally legitimate. To any other law, order and authority they may be outright rebellious. The aim therefore is to establish the legitimacy of The Leader, at which point all other law, order and authority can be dismissed as illegitimate.
Hence a lot of the rhetoric coming out of the US right wing, which is specifically targetted at attacking the legitimacy of the state and various actors associated with the legal cases, because that's what resonates with their voters. The laws of the land pose a potent alternative source of authority and so challenge to the authority of Trump, therefore they must be assaulted and degraded to establish the authority of Trump. As a measure of how far this goes, bear in mind that was the message even when Trump was president, in the form of all that 'deep state' baloney.