Since it's mid-summer in Tennessee, many people are enjoying outdoor gatherings with friends and family, perhaps having barbecues or picnics by the lake, or just having a few people over for a late night swim in the backyard pool and a few cold drinks. That latter part can lead to problems if you're not careful. A sure fire way to interrupt summer fun is getting pulled over and charged with drunk driving.
Having a glass of wine or a couple beers at a backyard party, however, doesn't necessarily mean that if you then get behind the wheel of a car to drive, you'll be breaking the law. There are typically many factors involved, although the only thing a police officer needs is reasonable suspicion to make a traffic stop (i.e. your car drifted toward the center yellow line on the road.). In the long run, if you're well-informed and prepared ahead of time, you shouldn't have trouble steering clear of intoxicated driving.