If you have a commercial drivers license, you should NEVER drink then drive. Why not?  Because of the severe consequences a DUI conviction has on your ability to drive a commercial vehicle. First, understand that you do not have to be driving a commercial vehicle to have your license affected.  Any moving violation, even in your personal car, affects your ability to drive commercially, but a DUI especially affects you.  How? 1. For a first DUI conviction your CDL is disqualified for one year; 2. However, if you refuse to take the state administered test, and your license is suspended administratively, your license is suspended for life! 3. A second DUI conviction also results in a lifetime suspension. So, hopefully you can see the importance of finding a qualified DUI defense attorney to aggressively defend a DUI charge.