I'm not passing judgement on anyone but I believe a person can be "impaired" and remain legally not under the influence. Many people react differently to alcohol than others. I'm not sure the word "tolerance" is an apt description as it implies there is no effect until a certain threshold. The .10 rule, or is it .08? (in CA anyways) is an arbitrary number that only determines whether a driver is legally under the influence.
Drive safely,
Sherwood Lee
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