Ben Garrison's cartoon attempting to make the case for civic nationalism instead tends to demonstrate its utter hopelessness, and rather effectively makes the case against it.
The Alt-Right is correct and the Alt-Right is inevitable. You can no more instill an instinctive respect for the U.S. Constitution, the Common Law, and Anglo-American culture into immigrants, no matter how long they are resident in the USA, than you can instill Rohinga values into Americans during a visit to a refugee camp in Bangladesh.
Think about it. Do the Jews, the Italians, the Irish, or the Scandinavians value small government today, even after more than 100 years of residence in the USA? No. Not even a little bit. They have learned to speak English, but they have never learned to value limited government. They are not, they have not been, and they will never be Americans in the original sense of the term, which is simply another way of saying "British colonist".
Hence the references in the Declaration of Independence to "ties of consaguinity" and "British brethren" and "King George". The American revolutionaries were not declaring independence from Gustav II of Sweden, Emperor Joseph II of the Hapsburg Empire, or Alvise Giovanni Mocenigo, the Doge of Venice.
The Mexicans, Chinese, Japanese, and various and sundry other post-1965 immigrant groups aren't going to become Americans either. Not now, and not in 10 generations. They will NEVER accept or respect the historical Anglo-American values upon which the country was founded.
The point is that there is no "fractured America". It is the USA that is fractured into America and various flavors of Not-America dating back to the mid-1800s. It worked, for a while, because the American residents sufficiently outnumbered the Not-American residents while immigration was almost entirely shut down between 1920 and 1965. They don't outnumber them anymore, which is why the USA will never be synonymous with America again.