According to the Conservative Intelligence Briefing website:
On the Republican side, Senator Marco Rubio is out front at 27% with Congressman Paul Ryan in second place at 18%. After that, former Senator Rick Santorum (14%), Senator Rand Paul (13%) and Governor Chris Christie (12%) are in a tight race for third place.
Among Republicans who have previously attended a caucus, Rubio leads Ryan 29%-21%. However, among Republicans who plan to attend their first caucus in 2016, Ryan’s support drops to 7%. Paul (22%) and Santorum (19%) fill the void.
Among voters who consider themselves “Very Conservative”, Rubio leads with 32% followed by Ryan at 18%, Santorum at 15%, and Paul at 14%. Among the “Somewhat Conservative”, Rubio’s lead over Ryan shrinks to 3% (25%-22%).
The gender splits are revealing. Paul scores 17% among Men but his support drops to 8% among Women. Ryan seems a similar drop among Women (14%) compared to Men (22%). Conversely, Santorum (15% with Women, 12% with Men) and Christie (13% with Women, 11% with Men) do slightly better with Women.