Whether he can sue them in his own state depends upon whether the defendant maintains a physical presence in the plaintiff's home state or in the alternative if the defendant subjected itself to the long arm jurisdiction of the forum state. If the defendant maintains what is termed legally as a physical presence within the forum state the chances of not having to defend against a jurisdictional challenge are pretty good.

On the other hand if the plaintiff is relying on his state's long arm statute he is almost certain to invite a motion to dismiss for lack of jurisdiction. Defending against the motion to dismiss is a crap shoot. It could go either way. In this scenario the plaintiff can avoid the problem entirely by suing the defendant in his home state.

With respect to the long arm statutes...many states provide that the defendant has subjected himself to the long arm jurisdiction if the defendant transacts business within the plaintiff's home state. The rub is the definition of  what constitutes transacting business within the state. In states such as Connecticut there seems to be a distinction between suits sounding in contract breach and torts. In contract breach claims the defendant would need to physically enter the state of Connecticut in order to become liable within Connecticut. (ex. Massachusetts salesman entering Connecticut to drum up business). The Connecticut courts have ruled that transacting business over the phone, fax or email while the plaintiff and defendant are located in different states does not constitute the defendant's entering the state of Connecticut for purposes of a contract breach suit. Tort suits are a little more liberal with respect to whether such conduct would subject the defendant to Connecticut's long arm jurisdiction.