For me, the main part is that their self-serving is very rarely directly transferring money from unwilling taxpayers to themselves. Book deals or speaking engagement: basically milking their popularity like any other celebrity but you’re also free not to pay them. Insider trading: murkier since I’m indirectly harmed financially by the uneven playing field. But at least there are attempts at preventing it like the Stop Insider Trading Act (H.R. 7008).
But suing your own administration for Billions is a level of brazen kleptocracy that should make other politicians blush. Kinda like the difference between someone noticing the cashier make a mistake in their favor and not saying anything vs. Suharto-level thievery.