Sounds reasonable enough...
No, it's not. That was a wish list from a batch of bureaucracies infested with leftists. It was not the budget Walker signed into law after a string of line-item vetoes. Trump knew it.
“Trump knew it”
Not necessarily so. Trump notoriously doesn’t dig and that would be a most misleading factoid to get. Trump would do well to apologize for the misunderstanding, though.
One could still ask why he had to use the line item veto — why he didn’t negotiate a sane budget to just get his John Hancock upon (and that might be Trump patting himself on the back for how he cuts deals).