Polls at times found the majority of Americans opposed the Civil Rights Movement. Polls found the majority of Americans opposed Dr. King. Because the majority of Americans in a racially divided nation support something does not make it just nor constitutional.
Also, the language of the polling matters. This polling says Americans are "open to" US troops being sent to "help," not the imposition of these troops on mayors and sovereign governors who are NOT asking for them.
Also, WHO the who we are, is as always in America the most revealing thing. White conservatives want this. Most black people, you know the oppressed minority whose dissent they are trying to repress, do not. 
