MoveOn admits: “[I]f younger, healthier people don’t participate, then costs will skyrocket and Obamacare will fail.”
...[R]ight-wing groups have launched a multi-million-dollar campaign to torpedo Obamacare before it even gets started. Their plan: Mislead young people about how the law works so they get scared and don’t enroll. The problem is that it really could work because if younger, healthier people don’t participate, then costs will skyrocket and Obamacare will fail.

MoveOn.org footnotes a Washington Post article, which explains that last sentence. From the Post Wonkblog article by Sarah Kliff: “Young adults tend to have lower medical bills, which would hold down premiums for the entire insurance market. If only the sick and elderly sign up, health costs would skyrocket.”...