Complex sentence: In 2003, the CARB, headed by Democrat Alan Lloyd, finally caved to industry pressure and drastically scaled back the ZEV mandate after defending the regulation for more than 12 years.
Split into simpler sentences: In 2003, the California Air Resources Board (CARB), headed by Democrat Alan Lloyd, finally caved to industry pressure and drastically scaled back the ZEV mandate. CARB had previously defended the regulation for more than 12 years.