Donald Trump doesn't show sympathy for many people—unless, of course, he's ending a bitterly critical tweet with an ironic "Sad!" (See, for instance, "Lyin' Ted and Kasich are mathematically dead and totally desperate. Their donors & special interest groups are not happy with them. Sad!")

But lately the Republican frontrunner has been expressing what appears to be true compassion for Senator Bernie Sanders. The latest example is a tweet urging Sanders to go rogue and run as an independent:

It's not the first time Trump has made such comments about Sanders' relationship to the Democratic Party. Just last week, during his victory speech after sweeping the New York primary, Trump cast Sanders as a victim of the "rigged system" in politics. "By the way, I am no fan of Bernie," Trump said, "but I’ve seen Bernie win, win, win, and then I watch and they say he has no chance of winning."

Of course, Trump's statement ignores the fact that Hillary Clinton has amassed millions more votes than Sanders, despite Sanders' winning streak in late March and early April.

Trump may seem an unlikely ally for Sanders. After all, they appear to stand at polar opposite ends of the political spectrum. Where Trump plans to deport 11 million undocumented immigrants, Sanders supports a path to citizenship. While Trump has claimed the concept of climate change was fabricated by the Chinese, Sanders has called climate change the greatest national security threat of our time.

Despite those differences, however, both candidates embody the populism that has radically altered this election cycle. Everyday Americans, far removed from the political elite, are now driving the national conversation, and their disdain for "the system," however they define it, has created an unlikely overlap between Trump and Sanders supporters.

Sanders' campaign manager Jeff Weaver, for his part, sent a fundraising email to supporters today, asserting that the Clinton camp is going out of its way to align Sanders and Trump in the public eye. In the email, Weaver reminds supporters that "there is one candidate in this race Donald Trump said would make a 'great president,'" referring to a 2008 blog post Trump wrote about Clinton.

While Trump's empathy may be completely unwanted as far as Sanders is concerned, it's in Trump's best interest to continue laying it on thick. As a Clinton nomination grows ever more likely, it seems Trump is angling to absorb at least some of Sanders' impassioned supporter base in the remaining primaries. And of course, a third-party run by Sanders could peel off votes from Clinton in the general election. Trump may appear to be backing Sanders, but really it's still ultimately about so much winning.