The real story of this next election cycle will be that of a "generational war" and the passing of the torch to the next generation... Although they have not been as reliable a voting block as the seniors or boomers, their involvement in the electoral process was part of the reason that Barack Obama won in 2008.
Conservatives should be hoping that there's a candidate in the race who's campaigning for stronger families and small businesses, a stronger middle class and reduced concentration of power. A Warren candidacy would be so much more interesting than the dynastic machine politics of Bush Mk III v Clinton Mk II.
Paul is a divisive politician, beloved by younger Republicans, untrusted by religious and social conservatives and feared by the party establishment. Yet it is his non-interventionist worldview that represents the biggest threat, particularly to the neocons for whom perpetual war offers the healthiest returns.