Just to step back a moment, the reason it was such a terrible idea for Trump to have pulled the U.S. out of the Partnership is because the very reason for its existence was to form a united front that would protect the member countries against unfair trade practices by China. Gee, why could that ever be an issue...
Jump forward to today. After Trump brought forth tariffs on China, and China responded with some harsh, harmful tariffs on the U.S., suddenly Republican senators and congressman are finally speaking out against Trump -- and vociferously -- because their constituents are going to be badly hurt. And within the week...gee, there he is, Trump bringing up talking with the TPP folks about rejoining.
He sent out a tweet on the subject later in the day, trying to somehow put a good spin on it all, how he's looking to negotiate a better deal for the U.S., which is all he wanted all along. Of course, why he thinks he can negotiate a better deal now rather than at the time before he pulled the U.S. out of the Partnership so that we wouldn't have had to leave is anybody's guess. And why by chance it's "now," right after China imposed tariffs on the U.S is not going to slip past the notice of the TPP leaders. They're pretty smart guys.
Make no mistake: The TPP has gotten along just fine without the U.S. after Trump left. There is no particular reason for them the give the U.S. a "better deal." Indeed, as I said, they know why he wants to rejoin now, so he had better be prepared to beg to let America back in, after having started a trade war with China.
After having written the above, we now have this article from the New York Times. "Trump Wants Back Into the TPP. Not So Fast, Say Members." You can read the article here.