For too long has this man been allowed to violate the law and escape justice, surviving with threats to create a state of lawlessness (which is already in place anyway). Chief Minister Vilasrao Deshmukh's fears/apprehensions/inability to arrest this pseudo-terrorist has also aggravated the situation.
The state Government has to act fast: arresting Raj will be the first step, using, if necessary, harsh force to contain the assured violence will be the second. Undoubtedly the Congress will lose the next election if it does this: but that is a risk it will have to take, for it is a matter of National integration and goes way beyond politics.
The Union Government is also obliged to do something, since the Centre is supposed to maintain National unity as per the Constitution. The letter written by the PM to the CM is a good step: more needs to be done.
This is an emergency: Raj Thackeray has threatened to agitate (read, create an environment of lawlessness and havoc) is 'outsiders' are included in the voters' list. This is the last straw: he cannot overrule the Constitution no matter who he is fighting for. This man is a terrorist, a danger to the Union and a disease that must be destroyed before it destroys everything else.