First of all, you should know that all 50 states have enacted implied consent laws. So, despite what you might have heard, implied consent laws provide that any person who operates a motor vehicle has implicitly consented to a chemical test of his or her blood, breath, urine, or saliva for the purpose of determining the alcohol content of the blood. Therefore, you DO NOT have the right to refuse a breathalyzer without consequence (such as automatic suspension of your license) so long as a police officer has arrested you or taken you into custody for operating a motor vehicle while intoxicated or under the influence.
Nevertheless, the police officer must have reasonable grounds prior to the arrest that you were driving in an intoxicated condition. Reasonable grounds can be anything from straddling the center lane, appearing drunk, weaving, swerving, or stopping without cause in a traffic lane.
What a police officer cannot do is stop a driver for no reason, or simply to check license and registration, unless, of course, the officer has a specific reason to believe the driver doesn’t have a license or registration. Otherwise, stopping and detaining a driver for no reason is illegal, with one exception: Sobriety Checkpoints.