The conventional wisdom is that Donald Trump's decision to suspend the federal subsidies insurers say are vital to the survival of Obamacare is simply the latest manifestation of the current president's contempt for everything associated with his predecessor.

Haters gonna hate, after all. And who hates anything more passionately than 45 hates 44?

It seems at times as if obliterating every vestige of Barack Obama's legacy is the animating principle of the Trump White House. We can complain that Trump's pathological hostility has put universal healthcare, renewable energy, and South Korea's civilian population at risk, or we can be grateful that Trump doesn't hold Obama responsible for chocolate cake, labradoodle puppies and heated seats.

The White House is obviously frustrated at the GOP Congress' repeated failures to repeal Obamacare. Still, the question remains: Why is Trump targeting the elements of the Affordable Care Act that most benefit his supporters?

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The cost-sharing subsidies the president has pledged to end decrease premiums and out-of-pocket costs for lower-income workers who don't qualify for Medicaid but make up to 2 1/2 times the federal poverty rate. His decision will likely boost premiums for the 320,000 Michiganders who signed up for individual or small group coverage under Obamacare this year by an average of 26%.

Michigan isn't an outlier: According to an analysis by the Associated Press, nearly 70% of those who benefit from the subsidies scheduled for elimination live in states Trump won last November.

In fairness, ending the subsidies was originally the GOP Congress' idea. Republicans sued to block the payments three years ago on grounds Congress never formally appropriated the money to fund them.

But in recent months, as it became apparent how hard red state workers would be hit by an abrupt suspension of subsidies, many Republicans have urged congressional action to keep the subsidies flowing, at least until they can muster the votes to adopt an alternative health care plan.

U.S. Rep. Kevin Brady, the Texas Republican who chairs the powerful House Ways and Means Committee, has warned that millions of Americans may lose access to affordable health care just in time for next year's mid-term elections unless Congress takes action to fund the subsidies. Two Republicans in Michigan's congressional delegation, Rep. Fred Upton and Rep. Mike Bishop, have enlisted in a bipartisan campaign to restore them in exchange for a relaxation of the mandate that requires many small businesses to provide coverage to their employees.

Only the president (and the libertarian fringe championed by Kentucky Sen. Rand Paul) still seem determined to kill the payments and undermine the exchanges on which tens of millions of American's -- most from states that supported Trump -- purchase individual coverage. So, again: Why?

Perhaps the White House has heard about a new study published in the American Journal of Public Health, which notes a striking correlation between improved life expectancy and partisan preferences in the 2016 presidential election.

Boston University's Jacob Bor found that U.S. counties that enjoyed above average gains in life expectancy between 1980 and 2014 overwhelmingly voted for Hillary Clinton last November, while the majority of voters in counties that reported below-average life expectancy gains voted for Trump. In counties where life expectancy jumped more than seven years, Democrats saw their share of the popular vote increase by 3.5% between 2008 and 2016.

As anyone with an IQ as prodigious as Trump's must know, life expectancy has risen pretty much in tandem with access to good health care. And if improved access to health care makes a person more likely to vote against Republican presidential candidates, Trump might reasonably be interested in not making sure this better-health-longer-life-expectancy cycle doesn't become too, you know, robust.

But probably it's just the pathological hatred of Obama thing. The president really should get some clinical help for that, before the whole country's life expectancy is at risk.

Contact Brian Dickerson: bdickerson@freepress.com.