When I learned last Tuesday that Democrats, breaking with past practice, had dropped the word “God” from their party platform, I dispatched a message via Twitter: “God is mentioned in the 2004 Democratic platform 7 times. In the 2008 platform, once. In the 2012 platform, 0 times.” I included a link to the National Journal story where I’d seen the details.

Within moments, that tweet had taken off. To my surprise, it was retweeted hundreds of times – an early indication of the backlash about to engulf Democrats in Charlotte over their platform’s language on God and Jerusalem.

What really startled me, however, was the surge of responses I received from people who were glad to see God go unnamed in the Democratic platform. They didn’t say they don’t believe in God (though that may be true). Rather, they claimed that in the United States, politics and religion should have nothing to do with each other. Tweet after tweet seemed to take it for granted that references to God don’t belong in American public life:

“Democrats are getting the idea: politics are politics and religion is religion.”

“Is ‘God’ a political issue now? Separation of Church and State means nothing to you?”

“Good … church and state should be separate. Neither party should mention anything regarding religion.”

“I don’t get why this is even an issue. Why should religious beliefs have any place in politics?”

“The Founding Fathers would approve.”

In reality, the Founders would have been the last to suggest that appeals to God and religion have no business in political affairs. Far from asserting that America’s democratic system should be God-free, they regularly asserted the opposite.

“Of all the dispositions and habits which lead to political prosperity, Religion and morality are indispensable supports,” George Washington reminded Americans in his Farewell Address. “The mere politician, equally with the pious man, ought to respect and to cherish them.”

Years earlier, writing in Federalist No. 37 about the astonishing harmony reached at the Constitutional Convention, James Madison concluded that the delegates must have been guided by God. “It is impossible,” he observed, “for the man of pious reflection not to perceive in it a finger of that Almighty hand which has been so frequently and signally extended to our relief in the critical stages of the revolution.”

When Madison and the First Congress later crafted the Bill of rights, it was natural that the Establishment Clause be immediately followed by the Free Exercise Clause. Separation of church and state meant only that government was not to dictate any specific creed, or empower one sect over another. But Madison and the founders took it for granted that American democracy would be enriched by religion and its teachings.

Nothing is more normal than the invocation of God in our public life. “In God We Trust” appears on all US currency. The Almighty is acknowledged in every state constitution. Every president adds “So help me God” on taking the oath of office, and each has mentioned God in his inaugural address. Religious language in politics is as American as a Fourth of July parade.

And as bipartisan. Even before the G-word was restored at the convention, the Democrats’ platform had included a respectful plank about faith. Many who took to the podium in Charlotte made a point of mentioning religion. Elizabeth Warren cited Jesus’ admonition in Matthew 25:40 (“Inasmuch as ye have done it unto one of the least of these my brethren, ye have done it unto me”). San Antonio mayor Julian Castro, the keynote speaker, recalled how his grandmother would see him and his brother off to school, “making the sign of the cross behind us, saying, ‘Que dios los bendiga’ – ‘May God bless you.’”

Religious Americans these days may be more likely to vote Republican, but no ideology has a monopoly on the moral authority religion can supply. From abolition to the antiwar movement, religion has played an indispensable role in liberalism’s great causes too.

Would those who tweet their support for a wall between political and religious expression have made the same demand of the Rev. Martin Luther King, and the clergy who stood with him in the fight for racial equality? Would they want left-of-center “God-talk” silenced in the debates over budget cuts or gay marriage or immigration? Should Matthew 25:40 really be off-limits when Democrats talk about the poor?

In America, politics and religion are not strangers. Here faith and freedom go together, as we aspire, however imperfectly, to be one nation under God, with liberty and justice for all.

(Jeff Jacoby is a columnist for The Boston Globe. His website is www.JeffJacoby.com).