Perhaps, but the amnesty he granted played a huge role in making it the all consuming issue that it is now.
He had his hands full bringing down the Soviets and undoing the damage to the economy of the carter years with a demon666rat dominated congress behaving badly as ever.
Bush has his hands full with 9/11, fighting in Iraq and Afghanistan, dealing with a downed plane in China, dealing with N. Korea, Iran, Syria and Lebanon, fighting to keep the tax cuts againsts the Dems, fighting against the Dems to keep our soldiers funded, fighting for nominees he's named for various posts, etc etc etc. Presidents are always busy. Doesn't excuse Reagan's error in granting amnesty.