In the United States, the police are allowed to briefly stop everyone for a checkpoint and get their license. However, they aren't allowed to force you to submit to a breath test, to my knowledge. Even implied consent laws usually require probable cause to arrest someone before they're triggered. States that require individuals to perform field sobriety tests almost certainly must require at least reasonable suspicion. Forcing people to engage in lengthy testing just because an officer feels like making them do it is likely unconstitutional and certainly ripe for abuse.
Of course, field sobriety tests themselves primarily test for ability to follow instructions (which can be impaired by alcohol, of course, but can also be messed up because you're nervous). If a police officer tells you to stand in a position until he finishes giving instructions and then starts to demonstrate the test, if you're overeager to start right away even though he hasn't finished, you're pretty close to failing the test. All you have to do is not stand in the proper starting position or make one mistake on the test (for example, counting silently instead of outloud, not fully touching heel to toe on one step, lifting your arms out to the side instead of keeping them on your side). The tests themselves can actually be pretty overinclusive in creating evidence sufficient to prove DUI beyond a reasonable doubt.
