The premise of “romantic polytheism” qua religion is to take democratic consensus as a highest good.  It seems to me that this misses something important about the religious enterprise, namely the function of connection with an Other (the “wholly Other,” if one follows Rudolf Otto).  Put another way:  It may be that a representation of democracy (if not an outright embodiment of it) is needed as an object of religious activity, particularly if undertaken by a group.

In considering America as the ground of the religion, some possible “deities” seem viable:

• Liberty – We are used to seeing Lady Liberty not only in her incarnation as the “Statue of Liberty,” but also on American coinage and other civil uses.  Prior to the early 20th century, Americans were accustomed to the image of Columbia as the embodiment of the United States and specifically of its role as a new democratic nation in counterposition to Britain’s monarchy.  The iconography of Columbia draws on deeper traditions of democracy, e.g., the inclusion of the Phrygian cap from the Classical Hellenic world.
• The “Great Spirit” (or “Manitou”) – If “Liberty” or “Columbia” can represent the nation created by Europeans in North America, what of the Land itself?  And the people who inhabited it?  Although the “Great Spirit” associated in popular culture with the spirituality of the “American Indian” is a mix of oversimplification, stereotype, and Christian proselytization, there is–especially among the Algonquian cultures–an animistic tradition of seeing all things in the world as partaking of a shared spirit, often identified as “Manitou” or related terms.  There is a helpful resonance with the Deist views of many of the American “Founding Fathers,” which saw “God” as more or less identical with Nature.  More than that, though, offering respect to the indigenous cultures–and acknowledging the appropriation of their lands, often by genocidal means–seems essential to any systematic veneration of the American enterprise.
• The Founding Fathers – There is a deep tradition in Indo-European mythology and religion of emphasizing the way in which heroic ancestors achieve immortality through memory and the telling of their exploits by subsequent generations.  In addition to individuals offering due respect to the personal ancestors who preceded them, an honest and informed custom of acknowledging and celebrating the actual deeds and ideals of those who set in motion the tradition of American democracy seems critical.  The “Founders” have been appropriated in a haze of pseudo-history by political factions eager to apply the imprimatur of the sagacious, if imperfect, individuals who forged the nation and it is important to reclaim their words and deeds for what they were, not what we wish them to be.
• “Uncle Sam” – The embodiment of the United States as a nation (rather than of its underlying ideals), Uncle Sam has been around since the early 19th century.  He has become highly emmeshed in commercialism and militarism over time and risks dragging a spiritual enterprise into a caricature if not employed judiciously as object of veneration.

This small “pantheon” seems reasonable to approach as the objects of various ritual activities and none require a supernaturalist understanding to embrace.  All are able to be approached as the Romantic poets approached Nature and all its aspects and this comports well with the “Poet as Priest” aspect of Romantic Polytheism.