The hosts of The View, including Ana Navarro and Sunny Hostin, condemned Trump's use of the derogatory term.
Ana Navarro shared her personal experience with her intellectually disabled brother and recalled Trump's past mocking of a disabled New York Times reporter.
Governor Walz, whose son has learning disorders, appeared on Meet the Press to state that Trump's language is damaging and normalises hateful behaviour.
The incident prompted an Indiana Republican state legislator, Michael Bohacek, to oppose a GOP-favoured redistricting effort due to his daughter having Down syndrome.