A writer at The Washington Post says the answer is yes:

First, it isn’t the 1950s anymore. As religion scholar Will Herberg noted in his influential 1955 essay “Protestant-Catholic-Jew,” at that time 68 percent of Americans were Protestant, 23 percent Catholic, and 4 percent Jewish. (The remaining 5 percent expressed no religious preference.) “Not to be a Catholic, a Protestant, or a Jew today is, for increasing numbers of American people, not to be anything.” According to a recent Pew report, those figures have declined to 51, 23 and 2. The remaining 20+ percent express plenty of preferences, including Mormon, Muslim, Buddhist, Hindu, Atheist and Agnostic. Not to be a Catholic, a Protestant, or a Jew today is, for increasing numbers of American people, to be something else just as worthy of citizenship. Second, the greatest threat to American freedom is no longer godless communism but “godly” terrorism — people who pledge their allegiance to God. Docherty noted that even Stalin’s Soviet Union could claim to be “one nation, indivisible, with liberty and justice for all.” Today, even a Taliban-led Afghanistan could claim to be “one nation, under God.” In his 1954 sermon, Docherty argued that Judeo-Christian America was engaged in “mortal combat against modern, secularized, godless humanity.” Today, pluralistic America is engaged in mortal combat against anti-modern, fundamentalist, religionized humanity. It isn’t our belief in God that makes us different. It’s our belief in the liberties (religious and other) enshrined in the Constitution. The American creed is faith in liberty for all, not the religion of most.

On some level, Waters is absolutely correct but he misses the most important reason why claiming that the United States is a “nation, under God” is inappropriate. It was expressed by America’s Third President:

Believing with you that religion is a matter which lies solely between man & his god, that he owes account to none other for his faith or his worship, that the legitimate powers of government reach actions only, and not opinions, I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should make no law respecting an establishment of religion, or prohibiting the free exercise thereof, thus building a wall of separation between church and state. [Congress thus inhibited from acts respecting religion, and the Executive authorised only to execute their acts, I have refrained from presenting even occasional performances of devotion presented indeed legally where an Executive is the legal head of a national church, but subject here, as religious exercises only to the voluntary regulations and discipline of each respective sect.] Adhering to this expression of the supreme will of the nation in behalf of the rights of conscience, I shall see with sincere satisfaction the progress of those sentiments which tend to restore to man all his natural rights, convinced he has no natural right in opposition to his social duties.

America, as Jefferson noted, is not a nation founded on a specific set of religious beliefs, but on the belief in the natural rights of man, from whatever source those rights are derived.