“As the nation went through this very rapid demographic change the question has been would older white Americans would essentially withdraw from the public sphere and not fund a new generation who did not look like their kids,” said Simon Rosenberg, president of NDN, a Democratic advocacy group. “You are going to see that basic dynamic play out in a very significant way under Trump. What Trump is doing is creating a wall around older white Americans: he is being an isolationist both within the country and without. He is trying to create walls between older white Americans and the new Americans who surround them.”

While the administration won’t produce a full budget until mid-March, it has already sketched out the central pillars of its strategies: a defense spending increase of $54 billion, offsetting cuts in other domestic spending programs, a major tax cut and limited or no changes in Social Security and Medicare, which Trump pledged during the campaign to defend.

By so overtly favoring retirement spending over other domestic federal programs, Trump has underscored the generational competition for resources that, as I’ve written before, represents a central if often unacknowledged tension in budget debates. Most of the key federal investments in the productivity of future generations are made through discretionary programs, like those that support education, training and scientific research.

The federal government’s support for seniors, by contrast, mostly flows through the giant entitlement programs for the elderly, Social Security, Medicare and Medicaid (which finances long-term care for lower-income seniors). Several entitlement programs also provide substantial benefits to young people and their working-age parents: that list includes Supplemental Nutrition Assistance Program (formerly known as food stamps), Medicaid (which, in addition to benefiting the elderly, provides health care for low-income families), the Children’s Health Insurance Program, and more recently the Affordable Care Act.

Setting the spending levels for these programs poses stark racial and political choices. The younger population that benefits most directly from investments in the productivity of future generations is increasingly diverse: minorities comprise fully 47 percent of all Americans younger than 30, according to 2015 Census data. Whites comprise nearly four-fifths of today’s seniors and almost three-fourths of all Americans older than 45.

These contrasting groups anchor each party’s electoral coalition. Whites over 45 provided a majority of Trump’s votes last fall, and about three-fifths of House Republicans represent districts where the share of seniors exceeds the national average. Meanwhile Hillary Clinton relied on big margins among members of the Millennial Generation and minorities (even though she did not quite match Obama’s overwhelming advantages on either front.) About two-thirds of House Democrats represent districts with fewer seniors than average.