Italian system is multi-party system with hybrid proportional representation. Very different.

The US operates on a "separation of powers" FPTP winner-takes-all system: once one party has lined up control of both houses, the Presidency and the Supreme Court, they can do almost anything, and (thanks to SCOTUS control) without regard to constitutional legality.

The last remaining bulwark is the Democrat states, which is why Federal troops have been sent in to intimidate them.