No it should not be lowered. I believe NJ lowered it to 18 years old a few years ago and it failed, miserably. NJ's drinking age is now back at 21 years old.
Not sure about New Jersey, but I do know that in many states the age was raised to 21 from 18 or 19 soley because the federal government threatened to withhold federal funds from states that did not do what the federal government wanted.
The feds did the same thing with DUI laws. The feds forced the states to accept a very low definition of DUI.