Yes it was. Because it's just as easy to say that Schumer and Pelosi knew going in they weren't going to give support for the wall.
Thus my point. They had already made their opposition to the wall clear long before they entered into any "negotiations" with the president. I think they made such sentiment clear even before the election. In fact, the case can be made that both sides knew where the other stood on immigration policy.
There was nothing specific agreed to at the time he "reneged". Both parties were adamant that no deal had been reached, as of this article, dated October 3rd of this year:
"Republican lawmakers who dined with the president Monday night cast doubt Tuesday on Trump’s talks with “Chuck and Nancy” — Senate Minority Leader Charles E. Schumer (D-N.Y.) and House Minority Leader Nancy Pelosi (D-Calif.) — about plans to protect eligible children of undocumented immigrants and make changes to the nation’s border security. Trump and the Democratic leaders agreed to work on legislation that would couple plans to protect dreamers with legislation to bolster U.S.-Mexico border security, but not include the construction of more border wall. But no specific items were agreed to, and Democratic leaders say they are still waiting for Trump to submit ideas on how Congress should proceed."
Deal or no deal on DACA? Republicans say no. Democrats say not yet.
So, I assume the reason he pulled out of the negotiations is due to the inane stubbornness of the people he was negotiating with
in good faith. Let me repeat,
there was no deal for him to back out of.
Nobody altered a thing. Neither Trump nor Pelosi nor Schumer. I am not attributing the failure of the negotiations to some sort of underhanded tactics, I am attributing the failure of said negotiations to (from what I am reading) neither side willing to give or take on the matter.