Republicans and Republican leaning independents remain historically undecided about who they would support in the presidential primary. From Gallup:
Gallup finds a fairly high degree of uncertainty, with roughly one in five Republicans not having a preference even after being read a list of the likely candidates. That is a higher percentage of “no opinion” responses than Gallup has found at comparable points in prior GOP nomination contests.
The Republican base doesn’t seem enamored with their options right now. On net, that is probably a good thing for Mitt Romney. It is unlikely Romney will spark a massive wave a grassroots outpouring for his primary campaign but as long as no other single candidate does, he should be able to maintain his fundraising and organizational advantage in the field.