Vance literally wrote the forward to an upcoming book by Heritage Foundation President Kevin D. Roberts, the organization responsible for Project 2025. It is absolutely relevant.
I associate and even am friends with all kinds of people I don't agree with. Implying that I endorse their views just because I associate with them would be to assign motivations to me that I don't have.
Writing an introduction to someone's book, as a public figure, is lending your reputation to them - that's the point, to put your name and reputation behind them, and so they can show that off for credibility.
Vance literally wrote the forward to an upcoming book by Heritage Foundation President Kevin D. Roberts, the organization responsible for Project 2025. It is absolutely relevant.