Fifteen Asia-Pacific economies formed the world's largest free trade bloc on Sunday, a China-backed deal that excludes the United States, which had left a rival Asia-Pacific grouping under President Donald Trump. https://www.cnbc.com/2020/11/15/asia-forms-worlds-biggest-trade-bloc-excluding-us.html
When Obama spoke of having the US, rather than China, “write the rules of the road” on trade, this is the alternative trade pact (then still in negotiations) that he specifically warned about. https://www.washingtonpost.com/opinions/president-obama-the-tpp-would-let-america-not-china-lead-the-way-on-global-trade/2016/05/02/680540e4-0fd0-11e6-93ae-50921721165d_story.html
Pacific trade pact that Obama admin negotiated & that Trump then pulled us out of, TPP, was put into place without us, renamed CPTPP. To my knowledge Biden still hasn't said whether he would rejoin the deal. Here's what he told The Post during the primary: https://www.washingtonpost.com/graphics/politics/policy-2020/foreign-policy/trans-pacific-partnership-trade/
Biden had publicly supported TPP when he was VP; but important left-wing constituencies (e.g. unions) and pols (Sherrod Brown, etc.) opposed it. https://www.npr.org/2015/06/16/414831901/labor-unions-remain-steadfastly-opposed-to-trans-pacific-trade-measure
Since then, however, many of these same unions & pols came supported Trump-negotiated NAFTA 2.0 deal (USMCA). Some of USCMA's major changes — relating to labor standards, environmental protections and e-commerce — were basically cribbed from TPP https://www.washingtonpost.com/opinions/trump-didnt-blow-up-our-trade-system-whoop-de-doo/2018/10/01/2137be18-c5b7-11e8-9b1c-a90f1daae309_story.html
So, unclear what any effort to rejoin (CP)TPP today would look like -- & what pre-conditions left-wing constituencies might demand. Or whether RCEP adds pressure. Reuters on RCEP: "no details on which products & which countries would see immediate reduction in tariffs"