The common political wisdom these days is that if Hillary Clinton wants to put Bernie Sanders’s hardcore fans in her column, she’d be smart to pick anti-Wall Street crusader Elizabeth Warren as her running mate—a move that could bolster her progressive bonafides on campaign finance and financial reform. But there’s at least one good reason to think that picking Warren in a bid to mollify Sanders’s voters would backfire, by alienating that other critical Clinton constituency: the Wall Street moneymen who are terrified of the Massachusetts senator and want to keep her as far as possible from the White House.

In interviews, Clinton has spoken highly of Warren, and the former Harvard Law professor allegedly sits high atop her V.P. shortlist. But several major Democrat donors, who declined to be named for obvious reasons, told Politico that they were prepared to bail on Clinton if she chooses Warren, the architect of the Consumer Financial Protection Bureau who has regularly called to break up big banks, re-implement Glass-Steagall, and get money out of politics—their money, in particular.

“ ... If you are going there with Warren, we just can’t trust you, you’ve killed it.”

One major bundler who raised millions for Clinton stressed that it wasn’t Warren’s ideas that scared Wall Street, but Warren herself: she’s a firebrand and relentless rhetorician who can grandstand eloquently about the financial system when the cameras are rolling, but seems to lack the nuanced understanding or legislative finesse necessary to get the proper reforms through Congress. “They would literally just say, ‘We have no qualms with you moving left, we understand all the things you’ve had to do because of Bernie Sanders, but if you are going there with Warren, we just can’t trust you, you’ve killed it,’” he said. They also believe that she would not help foster relationships between Congress, the White House, and the private sector.

The argument as to why a Warren V.P. pick would be a risky bet for Wall Street goes like this: Donald Trump, the presumptive Republican nominee, is so unelectable and unpredictable that even the National Rifle Association has had to distance themselves from his ideas. Few people, these donors believe, would ever vote for him, and will naturally come on board for Clinton in any case. “Picking Warren would indicate weakness and panic for no reason and make them look like they are running scared of Trump,” a Clinton confidante and Wall Street executive told Politico. “There will be plenty of time to galvanize the left and get them to come out. And Warren would be a nightmare to try and manage.” Better to capture anti-Trump centrists, this line of thinking suggests, than to cater to the Sandernistas.

Outside of finance, however, there’s a more pressing concern: “They don’t particularly like each other,” a prominent hedge fund manager told Politico. And despite Warren’s apparent love of attacking Trump on social media—attacks he hasn’t been successful at returning—any seeming apprehension between the two women on the trail could be used as fodder for their enemies. As The New York Times recently noted, actual chemistry between a presidential candidate and their running mate is crucial. In a 24-hour news cycle, it would be startlingly clear whether the two candidates dislike each other. Given that Clinton wants to cast herself as the “no drama” candidate, picking a veep who could startle some Democrats—even those deep-pocketed donors some on the left distain—may be too much of a risk to take.