From an interesting article on the Founders' era (https://www.theamericanconservative.com/articles/american-nationalists/):

"The safety of a republic depends essentially on the energy of a common national sentiment; on a uniformity of principles and habits; on the exemption of the citizens from foreign bias and prejudice; and on that love of country which will almost invariably be found to be closely connected with birth, education and family… In the recommendation to admit indiscriminately foreign emigrants of every description to the privileges of American citizens on their first entrance into our country, there is an attempt to break down every pale which has been erected for the preservation of a national spirit and a national character; and to let in the most powerful means of perverting and corrupting both the one and the other… To admit foreigners indiscriminately to the rights of citizens the moment they put foot in our country would be nothing less than to admit the Grecian horse into the citadel of our liberty and sovereignty."