Your point is well taken. There was much opposition to Wallace from within the Democrat Party.
What I meant to say (and didn’t explain myself too well) is that Wallace did have a chance to secure the 1944 VP nomination and didn’t act upon it. The book “American Dreamer” by John Culver explains what happened at the ‘44 National Convention.
Roosevelt, in typical fashion, hemmed and hawed to pro and anti-Wallace factions as to whether Henry Wallace would be on the ticket again in ‘44. His comments led both sides to assume that either (a) Wallace would be removed from the ticket or (b) Wallace would be the VP nominee.
Rexford Tugwell said it best about Roosevelt “He had a trick of seeming to listen, and to agree or to differ partly and pleasantly, which was flattering. This was more highly developed as he progressed in his career and it was responsible for some misunderstanding. Finally no one could tell what he was thinking, to say nothing of what he was feeling.”
An advisor comes into the Oval Office and outlines some proposals. FDR nods and tells him, "By golly, I think you're right!" The man leaves thinking FDR is in agreement with him.
A second advisor comes in with a diametrically opposed set of proposals. FDR nods and tells him, "By golly, I think you're right!" The second man leaves convinced FDR agrees with him.
Meanwhile Eleanor had been sitting quietly watching all this. After the second man leaves she explodes and chews out FDR for misleading the two men into thinking they had his support. He listens to her, then nods, and says, "By golly, I think you're right!"