So there's the phrase "Patriotism is the last refuge of the scoundrel".
It's originally credited to Samuel Johnson in 1775.
In 1774, he printed The Patriot, a critique of what he viewed as false patriotism. On the evening of 7 April 1775, he made a famous statement: "Patriotism is the last refuge of the scoundrel." The line was not, as is widely believed, about patriotism in general but rather what Johnson saw as the false use of the term "patriotism" by William Pitt, 1st Earl of Chatham (the prime minister) and his supporters. Johnson opposed most "self-professed patriots" in general but valued what he considered "true" patriotism.
What we see here is a similar example of telling someone they are 'unkind' in order to elicit a change in behaviour and loyalty to a particular set of values.
It needs not be an exercise in flag waving (but it is interesting to note the flag waving).
JR bringing it up at this point on day 4 of the second half of the hearing is very telling indeed.
It is the behaviour of a scoundrel at their last resort.