Those crossing over...and the independents who went for Huntsman will vote for Romney to help try and knock off the conservative candidates.
If all three conservatives get together however, I do not believe it will work. Outside of Michigan and Nevada, the conservative candidate could win Florida, Arizona, and on from there to Super-Tuesday and Texas thereafter.
Ron Paul's voterbase is a bunch of left-leaning kids and aged hippies, and will probably split to Romney, and to Obama. They merely cloud the process, and don't allow for a TRUE Conservative to step up in the process.