According to the article they link[1], the 1% richest is defined as earning more than $109,000 in 2015. So basically, they want to tax the people who already pay the most taxes. Actually rich people having the means to avoid paying taxes altogether, it's the educated middle class that's once again expected to pay for opaque, poorly managed, and unaccountable government programs.
Glad I live in Switzerland.
[1] https://www.oxfam.org/fr/communiques-presse/les-1-les-plus-r....