Democrats have a 50-plus-year history of overreaching when they have complete control in Washington. The draft party platform they released Monday suggests they’ll extend that streak should they win in November.

The party’s track record of committing unforced political errors is truly remarkable. They controlled both chambers of Congress and the presidency four times since the election of 1964: 1965 to 1968, 1977 to 1980, 1993 to 1994 and 2009 to 2010. Each time, they pushed for a set of programs (Obamacare, the Clinton health plan, the massive War on Poverty) that many in the party had long desired but that were not necessarily priorities of the centrist voters whose support they relied upon to win. In each case, the party suffered a tremendous defeat within four years of assuming power, giving Republicans control of at least one congressional chamber or the presidency.

Prudent heads would counsel caution in the fall, especially since former vice president Joe Biden’s main appeal is that he is not President Trump. The surveys that show Biden with large leads both nationally and in the swing states are accurate, but those leads are built on the votes of millions of mainly college-educated suburban white voters who just a few years ago eagerly voted for Mitt Romney and Republican officeholders up and down the ballot. There’s nothing in those data to suggest these people have suddenly discovered their inner socialist or are prepared to make serious personal sacrifices to advance the left’s agenda. Yet that is exactly what the draft platform would have them do.

Climate change policy is an obvious place to start. Polls show that fighting climate change has become a top priority for Democrats, especially liberal ones. Yet polls also show that voters generally support modest measures that don’t cost them much in the short term. Election results from a Democratic bastion, Washington state, back this up. Even though the state has not voted for a Republican for president since 1984 or governor since 1980, voters opposed two initiatives in 2016 and 2018 that would have imposed a modest carbon tax to combat climate change. The vote wasn’t close in either election, with opposition to carbon taxes winning by 19 and 13 points. If habitual suburban Democrats and independents outside liberal Seattle don’t like aggressive climate change policies, you can imagine what new Democratic voters outside Houston, Dallas and Atlanta think.

Despite that, the platform and a separate climate action plan proposed by Biden pushes forward. Biden’s plan says he will spend $2 trillion over four years to combat climate change. That’s $500 billion a year — more than the budget for any government program before the coronavirus pandemic except Social Security, national defense and Medicare. That’s an incredible amount of money that will spark fears about either unsustainable debt, an increase in taxes or both. It’s hard to imagine that the upper-income suburban voters whose support undergirds Democratic chances will stand for that over time.

Race policies are another place where Democrats risk jumping the shark. Americans are concerned about race relations and generally support reforms that will improve the lives of black Americans, especially in their interactions with police. They resolutely oppose reparations for slavery, on the other hand. Progressive political scientist Ruy Teixeira noted this recently, saying that white seniors — who, as a group, have been trending toward Biden in the wake of covid-19 — overwhelmingly oppose reparations. Yet the party’s draft platform states it supports creating a commission to study slavery reparations.

Defense policy is another example of prospective overreach. Many people believe the Defense Department wastes money; the draft platform echoes that sentiment and says that Democrats can provide more defense for less. Centrists may initially support this, but only if U.S. security remains strong. The increasingly aggressive global postures from China and Russia means this era could be a repeat of the late 1970s, when post-Vietnam fatigue inspired defense cuts that quickly became unpopular as the Soviets exploited U.S. weaknesses around the world. This was a major reason in Ronald Reagan’s rise, and remained a significant factor in the migration of blue-collar “Reagan Democrats” to the GOP for years to come.

Platforms and policy papers often come and go without much effect. But Biden’s campaign has been consistently signaling a strong leftward turn across the board since he effectively clinched the nomination in April. Biden wants to unify the Democratic coalition, but he is forgetting that the centrist voters he’s attracting don’t have institutional representation in party councils. If Democrats do sweep to power in the landslide polls currently project and Biden governs like he’s now talking, they might find their victory to be fleeting.

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