Politics is, in part, a mathematical art: Its practitioners only win by accruing enough voters to carry elections.

It is therefore odd that the Left continues to subtract voters from its ranks. Deliberately. And it does so in the name of “inclusion.”

In a Gallup Poll taken in May 2016, 41 percent of Democrats identified as moderate or conservative on social issues. Yet clearly, the national Democratic Party is veering hard Left on such matters as abortion, same-sex marriage, and transgender “rights.”

Rejecting Life

Consider the 2016 Democratic Party platform on abortion. It reads as if written by a clenched fist in a mailed glove: “We believe unequivocally … that every woman should have access to quality reproductive health care services, including safe and legal abortion — regardless of where she lives, how much money she makes, or how she is insured. We believe that reproductive health is core to women’s, men’s, and young people’s health and well-being. We will continue to stand up to Republican efforts to defund Planned Parenthood health centers. … We will continue to oppose — and seek to overturn — federal and state laws and policies that impede a woman’s access to abortion, including by repealing the Hyde Amendment.”

1984’s Ministry of Truth could not have decreed it better.

Federal funding for abortion. An end of all state restrictions on abortion-on-demand, through the ninth month of pregnancy (even Roe allows for the possibility of state laws against such). And abortion (“reproductive health”) is “core” to “health and well-being.” This is chillingly reminiscent of a statement by the co-founder of what became the National Abortion Rights Action League, Lawrence Lader, who wrote in 1973 that abortion is “central to everything in life and how we want to live it.”

Abortion is the most wrenching and disturbing example of the Democrats’ sharp turn to the Left, yet in terms of the political calculus employed by the DNC, it is emblematic of a certain stubborn denial of reality.

A Marist College poll released on January 23 found that “there is a clear bi-partisan consensus on limiting abortion to — at most — the first trimester, with a majority of Clinton supporters (55 percent) and more than nine in 10 Trump supporters (91 percent) saying they support such limits.”

The poll also found that “Among Americans overall, nearly three-quarters (74 percent) want abortion restricted to, at most, the first trimester. Among those who want restrictions, 74 percent want the Supreme Court to rule in favor of those restrictions. This equates to about 55 percent of Americans who support such action by the court.”

Based on these data, is it hard to surmise why Hillary Clinton and her denizens could not win in the Midwest, large regions of the industrial North, or, of course, the South?

Rejecting Labor

Social issues are just one aspect of the Democrats’ battle plan of subtraction. President Trump is now making substantial inroads with the leaders of organized labor, traditionally one of the Democratic Party’s most reliable constituencies. “Today, President Donald J. Trump gave continued hope to thousands of skilled craft construction professionals in America’s heartland for whom the Keystone XL and Dakota Access pipeline projects have been an economic lifeline,” said North America’s Building Trade Unions in a statement following their meeting with the President on January 24.

This follows former President Obama’s cancellation of these key energy projects over the past few months.

This follows the widely-reported abandonment of millions of lower-middle income voters to the Republican Party. As long-time Democrat insider Tad Devine said in a National Public Radio interview shortly after the November election, “those middle-class workers thought that our party was not speaking to them, to their issues, to their concerns, to their priorities — that we were not in touch with them the way we should have been.”

Those workers didn’t just think that — they knew it. As former Labor Secretary Robert Reich, a man of the Left, wrote right after the Trump victory, “Democrats have occupied the White House for 16 of the last 24 years, and for four of those years had control of both houses of Congress. But in that time they failed to reverse the decline in working-class wages and economic security.”

The political viability of the Democratic Party is dubious, at best. “Obama … managed to hold a coalition of leftist and centrist Democrats together, but that is already crumbling,” writes David Graham in The Atlantic. “There will be great pressure for the party to adopt a vision that draws on the populist success of both Trump and Sanders, but that pressure will meet opposition from party insiders as well as from the educated, well-to-do whites on whom the party increasingly depends.”

In 2013, President Obama rescinded his invitation to respected Evangelical pastor Louis Giglio to pray at his second inauguration because Giglio had once preached that marriage is the union of one man and one woman (a position held by orthodox Jews and Christians since the beginning of their faiths). Because he was not “inclusive” enough, Giglio was excluded.

Exclusion is not how to build winning political coalitions. But in taking radical stances on a host of issues, alienation has become the Democrats’ stock-in-trade.

It is far too premature to write the final obituary of the party of FDR, JFK, Bill Clinton and Barack Obama. But a first draft, at least, might be worth having on hand.