From "The Rise and Fall of the Third Reich":
On the day following the fire, February 28, he prevailed on President Hindenburg to sign a decree “for the Protection of the People and the State” suspending the seven sections of the constitution which guaranteed individual and civil liberties. Described as a “defensive measure against Communist acts of violence endangering the state,” the decree laid down that:
Restrictions on personal liberty, on the right of free expression of opinion, including freedom of the press; on the rights of assembly and association; and violations of the privacy of postal, telegraphic and telephonic communications; and warrants for house searchers, orders for confiscations as well as restrictions on property, are also permissible beyond the legal limits otherwise prescribed.
In addition, the decree authorized the Reich government to take over complete power in the federal states when necessary and imposed the death sentence for a number of crimes, including “serious disturbances of the peace” by armed persons.
Thus with one stroke Hitler was able not only to legally gag his opponents and arrest them at his will but, by making the trumped-up Communist threat “official,” as it were, to throw millions of the middle class and the peasantry into a frenzy of fear that unless they voted for National Socialism at the elections a week hence, the Bolsheviks might take over. Some four thousand Communist officials and a great many Social Democrat and liberal leaders were arrested, including members of the Reichstag, who, according to the law, were immune from arrest. This was the first experience Germans had had with Nazi terror backed up by the government. Truckloads of storm troopers roared through the streets all over Germany, breaking into homes, rounding up victims and carting them off to S.A. barracks, where they were tortured and beaten. The Communist press and political meetings were suppressed; the Social Democrat newspapers and many liberal journals were suspended and the meetings of the democratic parties either banned or broken up. Only the Nazis and their Nationalist allies were permitted to campaign unmolested.