The TPP was a disguised corporate takeover of national sovereignty, with supranational TPP courts deciding trade policies.
"ISDS would allow foreign companies to challenge U.S. laws — and potentially to pick up huge payouts from taxpayers — without ever stepping foot in a U.S. court. Here’s how it would work. Imagine that the United States bans a toxic chemical that is often added to gasoline because of its health and environmental consequences. If a foreign company that makes the toxic chemical opposes the law, it would normally have to challenge it in a U.S. court. But with ISDS, the company could skip the U.S. courts and go before an international panel of arbitrators. If the company won, the ruling couldn’t be challenged in U.S. courts, and the arbitration panel could require American taxpayers to cough up millions — and even billions — of dollars in damages" [0]
[0] https://www.washingtonpost.com/opinions/kill-the-dispute-set...