On December 19, 2019, the U.S. House of Representatives passed the USMCA with multiparty support with 385 votes (Democracy 193, Republican 192) to 41 (Democracy 38, Republican 2, Independent 1).  On January 16, 2020, the U.S. Senate passed the trade agreement by 89 votes (Democrats 38, Republicans 51) to 10 (Democracy 8, Republican 1, Independent 1) and the bill was forwarded to the White House for the signature of Donald Trump.  On January 29, 2020, Trump signed the agreement (Public Law No: 116-113).  NAFTA has been formally amended, but not the 1989 Canada-U.S. Free Trade Agreement, which is only „suspended.“   In addition, there is a provision that the agreement itself must be reviewed every six years by the three nations, with a 16-year forfeiture clause. The contract may be renewed for a period of 16 years during the six-year review period.  The introduction of the Sunset clause gives more control in the organization of the future of the USMCA in the hands of national governments. However, there is concern that this could lead to greater uncertainty.
Sectors such as automotive require significant investment in cross-border supply chains.  Given the dominant position of the U.S. consumer market, it is likely that this will put pressure on companies to establish more production in the United States, with a higher probability of higher production costs for these vehicles.  Growing objections within Member States to U.S. trade policy and various aspects of the USMCA have had an impact on the signing and ratification process. Mexico said it would not sign the USMCA if tariffs on steel and aluminum were maintained.  Based on the results of the November 6, 2018 U.S. election, it has been speculated that the greater power of Democrats in the House of Representatives could jeopardize the passage of the USMCA agreement.   Bill Pascrell, a senior Democrat, argued for changes to the USMCA to pass Congress.  Republicans have opposed the USMCA provisions that impose labour rights on LGBTQ and pregnant workers.  Forty Republicans in Congress have asked Mr. Trump not to sign an agreement that includes „the unprecedented integration of sexual orientation and the language of gender identity.“ As a result, Trump ultimately signed a revised version that required each nation only to „policies it deems appropriate to protect workers from discrimination in the workplace“ and said the United States would not be required to introduce additional non-discrimination laws.
 The Canadian government expressed concern about the changes that have occurred under the USMCA agreement.  On June 19, 2019, the Mexican Senate ratified the agreement (114 yes, 3 no, 3 abstentions).  Mexico`s ratification process will be completed when the President announces its ratification to the Federal Register.