More Republicans using popular ObamaCare option

President Obama touts it frequently, and some Republicans have said it's one of the provisions they would consider preserving if they were to replace the healthcare law.

Keeping children on their healthcare plans hasn't softened Republicans' attitudes toward the law. Public opinion of ObamaCare remains negative, driven largely by overwhelming opposition from Republicans that has not wavered in the three years since it became law.

Still, the heavy Republican participation in a high-profile ObamaCare policy contrasts with conservatives' efforts to suppress enrollment in the law's new coverage options.

Conservative advocates have printed "ObamaCare cards" that they distribute for people to burn, and they're urging young people not to buy insurance next year through newly created marketplaces. If young people stay out of the marketplace, premiums could rise significantly for everyone else and the law is more likely to be considered a failure.