One of the best articles ever written on any subject is by J. Harvie Wilkinson III, "Toward One America: a Vision in Law." (The Green Bag Almanac and Reader, published 2009; see also 83 NYU Law Review 323)
A 4th Circuit judge laments America's growing divisiveness and presents seven solutions. I'm not going to go into all seven recommendations, but here are some of my favorite parts of the article:
We judges are as a class bereft of acquaintance with the variegated and pluralistic country that we serve.
On the much maligned overreach of the commerce clause:
The silent commerce clause is an indispensable ingredient of national unity.
Let's restore a constitutional respect for community. It is futile to expect a healthy nation in the absence of a healthy community. Community instills within us the sense that we live for something larger and more meaningful than just ourselves...Communities are built around shared purposes and values, one of which is surely a respect and appreciation for individual rights. But there must likewise be the sense that individuals contribute to, as well as take from, this larger whole of which we as single persons are but parts. To enshrine a sanctity of self in our founding charter without textual or historical warrant may be just as pernicious as the attempt to enshrine the discrimination against those whose personal choices may for good and legitimate reason fail to conform to the majority's own. On many of the great questions of the day, our Constitution is consciously agnostic. Its enumeration of rights is significant, but finite. Its grant of powers to representative government is formidable, but it does not prescribe what substantive ends the exercise of those powers must embody. To bend our Constitution in the direction of autonomy or collectivity is detrimental to our national health.
The search for One America requires less polarization, but not necessarily less partisanship. The two must be distinguished... Partisanship is more of a mixed bag. It can easily proceed too far, but it can also promote vigorous debate and frame electoral choices.
If you get a chance, do look up the full article. Required reading for every American.