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.  Republicans and the president complained about the time it took to conclude the negotiations, but the discussions resulted in a rare mix of support for a trade deal. More of that? “NAFTA lite”: The trade deal between Trump and Democrats looks like the president`s “worst” trade law, now called USMCA, a day after Trump signed a new trade deal with China, which defused trade tensions between economic powers.
Gordon Hanson, an economist at Harvard Kennedy School, said studies have shown that average incomes in all three countries have increased as a result of the trade agreement, although they are low. But the benefits of the agreement were very unevenly distributed among the United States. The result of a rare demonstration of cooperation between parties and cross-borders in the Trump era of global trade conflicts, the agreement was colored the same day he became the fourth U.S. president in history to make a formal impeachment proceeding. On March 13, 2020, the House of Commons passed The USMCA Implementation Act C-4 before being exposed for 6 weeks due to the COVID 19 pandemic. Due to “exceptional circumstances,” the third and final reading of the act was passed in the absence of a roll call vote, as part of an omnibus adjournment motion that was unanimously adopted by all members present.  Prime Minister Justin Trudeau was not present because he was at home in self-isolation after his wife, Sophie Grégoire Trudeau, tested positive for a covid-19 infection. On the same day, the Senate passed the first, second and third readings of the recorded voiceless legislation, and Governor General Julie Payette signed it shortly thereafter and concluded that Canada would ratify the legislation.    On December 10, 2019, the three countries reached a revised USMCA agreement. On January 29, 2020, Deputy Prime Minister and Minister of Intergovernmental Affairs Chrystia Freeland introduced the USMCA C-4 Transposition Act in the House of Commons and passed the first reading without a registered vote.
On February 6, the bill passed second reading in the House of Commons by 275 votes to 28, with the Bloc Québécois voting against and all other parties voting in its favour, and it was referred to the Standing Committee on International Trade.    On 27 February 2020, the committee voted to send the bill to Parliament for third reading, without amendments.