[nicolas_t]

The education level of the average taxi driver is usually not very high and racism is not evenly distributed among educated and not very educated people.

So even if there's 20-25% of people voting FN (the racist party) in France, the percentage of people with a relatively lower level of education is much higher.

And the other aspect of this is that people tend to not often talk with people of lower socio-economic level so talking to Taxi driver is one of the few occasions where people end up talking with people with drastically different level. (The same effect also happens in Hair Salons).