This whole thread is good, and a reminder that Tom Cotton’s use of history was woefully ignorant.
In addition to the points @justinjm1 lays out, I'll add that Cotton cherry-picked this quotation from Eisenhower on Little Rock but robbed it off the proper context. 
@justinjm1 Here's the full letter, which Eisenhower sent to segregationist Democratic Senator Richard Russell of Georgia.
As you can see, Ike noted that he sent in federal troops because Faubus had used the Arkansas National Guard to defy a federal court order *and* refused to use his state's police powers to protect "persons who are peaceably exercising their right under the Constitution."
Ike said he had to do so because it would be "tantamount to acquiescence to anarchy" to have *no* police presence protecting those citizens in Little Rock but also because -- in the part Cotton lopped off -- it would mean "dissolution of the union" to flout federal authority.
And you'll note at the end that Ike sharply drew a line between different rationales for use of force.
Hitler, he said, used force "to further the ambitions and purposes of a ruthless dictator." Ike said he acted "to preserve the institutions of free government."
Hitler, he said, used force "to further the ambitions and purposes of a ruthless dictator." Ike said he acted "to preserve the institutions of free government."
Defending the courts, upholding the constitutional rights of ordinary citizens, and preserving the institutions of free government.
Those were Eisenhower's reasons for -- reluctantly -- sending in federal troops. He didn't do it readily. He didn't do it eagerly.
Those were Eisenhower's reasons for -- reluctantly -- sending in federal troops. He didn't do it readily. He didn't do it eagerly.
