If she helps Romney get the nomination, there is probably something in it for her. Romney is paying off Pawlenty's debt. Romney needs Bachmann as much as Bachmann needs Romney. They both are sellouts.
>>> There are two possible reasons for Bachmann to be helping Romney...
Other then each has a common need to knock Perry down to have a shot at the nomination I am not seeing the coordination you imply. In any event I referenced the supporters on their own fading away from Bachmann and towards Romney. If she told them to do this I haven’t heard of it.
As illustrated by the Bachmann supporter exodus Romney as the great bogeyman doesn’t seem to exist outside a narrow and probably not particularly vital slice of the tea party. As best I can see it for those who get most hysterical over Romney, they only have the Perry option. Anything else they do is a vote for Romney, either directly or indirectly. Not that this has generally sunk in yet.