It was the most effective way to bolster Democratic unity.

On the streets of Philadelphia Monday, a lot of Bernie Sanders supporters made the case, to me and others, that there was no difference that amounts to anything between Donald Trump and Hillary Clinton. In this telling, they’re both oligarchs propping up a rigged system that must be dismantled before needed change can be achieved, and have both demonstrated deeply reckless foreign-policy judgment.

One implicit message on the first night of the Democratic convention: Even if you regard both major-party candidates as economic and foreign-policy disasters, recall the undocumented immigrants that stood on the stage, the black man with a Latino wife, the first black First Lady of the United States, the embrace of LGBT activists, and try to claim that there’s no difference between Hillary Clinton’s America and Donald Trump’s America. As if any Democrat could forget it, the DNC aired clips of Trump to remind everyone that Hispanics, Muslim Americans, and African Americans can all expect him to stoke racial tensions more nakedly than any other mainstream politician in the United States would dare to attempt in 2016.

Trump’s notable transgressions created an opportunity for Democrats.

For better or worse, identity politics, broadly construed, is the best way for Hillary Clinton to distinguish herself from her rival in a way that helps her to solidify intra-Democratic support. One part of that message, though she would never put it this way:

If you refuse to back me, Bernie Sanders supporters, you won’t just be making a statement against my economic and foreign-policy visions, or positioning yourselves for future runs at power in the Democratic Party, you’ll be doing so at the cost of consigning those Hispanics, Muslim Americans, and African Americans to bigoted policies and appeals that rightly alarm many in their communities and beyond.You’ll bring about more deportations, a potential religious test for immigrants, a doubling down on policing that leads to innocent deaths … and who knows what else? You’ll empower a bigoted man whose words have already inspired a hate crime, giving him the biggest megaphone in the free world.

I find it distasteful that Hillary Clinton has put Democrats in this position. And yet, I can’t refute the logic. I really do think Donald Trump represents a threat to minority groups in a manner totally distinct from a George W. Bush, Mitt Romney, or Ted Cruz.

I wonder if it will cost him the election.