Might help him get elected, but just getting elected isn’t everything. As Paul Ryan said, politicians should be in office for more than the perks.
If he’s not behind some variation of the Ryan plan, then, like everyone else, he’s got two options: Raise taxes significantly on the middle class or let the country go bankrupt. Those options don’t change just because he’s The Donald.
Then again, I doubt any Republican presidential candidate will strongly endorse the Ryan plan, either. They’ll say something weak like “it’s a good start to a national conversation” or something. The right thing here is definitely not the popular thing, and I doubt many candidates will tank their chances for the sake of honesty and integrity.
Think Progress has a bit of a hit piece on Trump, claiming that he has previously called Reagan a “con man” who “couldn’t deliver the goods” in his book The Art of the Deal, but curiously enough, while they do show an image from one page, they don’t show the page that contains that quote.
…But the quoted passage does indicate misgivings about Reagan, and demonstrates Trump’s basic politics: He is and always was a bit of a centrist and default-Democrat and populist at heart. Supposedly now he’s a recent convert to some form of conviction conservatism but it’s hard to believe that Donald Trump — who has the ego you’d guess a billionaire might have — has suddenly realized that he’s been wrong all of his life and has changed his opinions on everything.