Most of the outside money has poured in from fellow Unionistas panicking at the thought of the loss of all those union dues around the country. Since Walker's reforms, membership in the public employee unions has dropped 54%....that's a pretty huge hit in their DNC Fund Raising Machine...but reflects the real "value" the unions members perceive they receive from the union. 62,000 union members down to 28,000....impressive "win" for Walker!
As for recalls, the incumbent has no control over what some rabid special interest might conjure up to oppose him. The proof will be in the election pudding.