What reason did president eisenhower give to the nation for sending federal troops into arkansas to protect the little rock nine?

When the Little Rock Nine were attempting to go into the school, rioting and racial slurs, as with the Children were being assaulted. Eisenhower believed that the Governor had agreed to let the Nine enroll, so the ORIGINAL National Guard stood there and enforced order, well, the Governor wanted the black children to stay out of the white schools. 
When word got BACK to Eisenhower, he made it to where the National Guard was there to make sure the Little Rock Nine were able to enroll and go to classes. 
A lot thought that Eisenhower went too far, and a lot thought he didn't do enough.