in part:
But the closed door negotiations between a select group of Democrats and Mr. Lighthizer gave them an opportunity to secure multiple policy changes related to prescription drug pricing, the environment, labor protections and dispute settlement.
That included removing a provision that Democrats criticized as a boon to the pharmaceutical industry. Democrats had objected to provisions governing intellectual property protections for new pharmaceutical products, in particular an advanced class of drugs called biologics, which were given 10 years of protection from cheaper alternatives. Congressional Democrats said those measures could undermine efforts to make American health care more affordable and the revised deal strips out that 10 year protection.
Democrats have also been eager to lock in provisions that they see as improvements on the original NAFTA, and provide more certainty to the businesses in their districts that depend on the pact.
...
Besides updating rules for digital commerce, Mr. Trump’s USMCA has made other changes generally sought by Democrats, like raising the threshold for the proportion of a car’s value that must be made in North America in order to qualify for the pact’s zero tariffs. It also contains provisions designed to strengthen Mexican labor unions and roll back a special system of arbitration for corporations long opposed by Democrats.
http://www.nytimes.com/2019/12/10/us/politics/usmca-trade-deal.html