How would you even 'force to be a race' ?

You can force people's gender by criminalizing gender affirming care

Do you think banning blackface is remotely comparable?

Whiteness is an exclusionary concept, it's entire purpose is to create an in-group and out-group.

Whiteness as a social structure is perhaps the most pervasive descriptor of difference, being, and non-being. Structures of whiteness and being formally delimit the identities, bodies, and lives of non-white people. Frantz Fanon recognizes this in his depiction of identity in the book Black Skin, White Masks.

because nobody's black or white. These categories solely represent ethnicities considered desirable vs undesirable. Irish people weren't white.