Chaffetz's point was not about moderating policy. He's one of the most extreme members of Congress. He just wants a fresh advertising approach that will reach young people better. Essentially, he thinks young people are so dumb that they will vote Republican if they can just convince Justin Bieber to endorse them. Fact is, conservative policies since Reagan have screwed most young people sideways. Wealth is now so concentrated that most of are fighting for the scraps that will allow us to pay off our college loans. Take heart, GOP. You may face political destruction, but only because you've succeded beyond anybody's expectations at strengthening America's aristocracy.
Of course huge numbers of college students were also Paulites. Following your train of thought his policies would be even worse for young people, but he was beating Obama with them in some polls. In the end its the GOP's image and non-economic issues that drive college students to the Democrats.