Backlash against the Protect Illinois Communities Act

Some local law enforcement agencies have pledged not to enforce Illinois' new law that bans semi-automatic rifles.

What exactly does Illinois’ new law ban ?

Last week, the state of Illinois passed a new law, known as the Protect Illinois Communities Act, which prohibits “the sale and distribution of assault weapons, semi-automatic rifles, including AR-15s, high-capacity magazines and switches” within the state. However, at least 85 of the state's 102 sheriffs have vowed not to enforce the law to different degrees.
History of the AR-15

Why are some local law enforcement agencies refusing to abide by it ?

The new law does not require current owners of such firearms to turn them in, but they will have to register them with the state. The law was passed by the state's General Assembly and signed into law by the governor, but some law enforcement officials and lawmakers are refusing to implement the new restrictions.
10 years of gun legislation since Sandy Hook

Some county sheriffs have publicly declared that they will not enforce the law, citing it as an abuse of power or a violation of their oath to protect citizens' Constitutional rights. This stance is supported by many Republicans in the state, as well as gun shop owners and the National Rifle Association (NRA).
New gun and ammunition merchant code