If one were to ask Hillary Clinton why she spent so much of her campaign sequestered in fundraisers with the ultra-rich, she would no doubt point to cold-blooded electoral necessities. Campaigns are expensive, and you must hunt where the ducks are. In an age of extreme wealth inequality, that means the plutocrats.

And it is true, campaigns — presidential ones especially — cost money. But there is a strong case that taking money from the ultra-rich in particular is an electoral handicap for Democrats. For even the most hardened, cynical Democratic operative, it's time to think about ditching the donor class.

The most obvious piece of evidence is Clinton's campaign itself, which outspent President Trump's by something like 2-1 and still failed. You could argue that was a fluke: Perhaps Clinton would have won if not for then-FBI Director James Comey effectively trying his best to get Trump elected, the political press' hate grudge against the Clintons, Russian meddling, and other odd factors.

But regardless of where one lands on that argument, there are more fundamental reasons to be suspicious of big donor cash. The first is that it comes with big, and potentially very unpopular, strings attached. Michael Bloomberg, for example, is reportedly planning on spending some $80 million on Democratic candidates in the 2018 midterms — but only on people who share his weaselly centrist politics (like, er, Republican Peter King). What that means policy-wise is unclear, but at an informed guess, it means big cuts in social programs so as to reduce the deficit, and maybe some kind of intensely irritating nanny state thing.

Social Security, Medicare, and Medicaid are all extremely popular. Virtually no one supports cutting those programs. Adopting milquetoast centrism for money means abandoning potentially election-winning stances, like the increasingly popular Medicare for all, and possibly even espousing severely unpopular ones.

Or take Haim Saban, a Democratic megadonor. He has one issue, and that is the ferocious defense of Israel no matter how many children's legs have been blown off. He directs his donations with the frank purpose of purchasing Democratic allegiance for this view. Now, Israel policy may not be all that directly relevant politically, as foreign policy generally doesn't move that many votes (though Democratic voters are increasingly suspicious of Israel). But it does concretely help the Republican Party, because the extreme right-wing government of Israel has tried to help the GOP in the last two presidential elections. If Democrats could get clear of Saban and similar donors, they might be more amenable to the idea that the Israeli government shouldn't be getting so many gigantic sacks of U.S. foreign aid cash if they're going to meddle in American elections.

But in general, one should be suspicious of the political salience of anything the top 0.1 percent thinks or wants. It's practically guaranteed to be unpopular among the broad population, and probably a policy disaster to boot.

The second is that campaign cash has diminishing returns. A candidate needs a decent initial sum to be competitive, depending on what she's running for (a state legislative campaign only needs maybe $10,000 or so to get off the ground, while a presidential race will obviously need many tens of millions). But beyond that seed money, the additional value of more campaign cash declines fast — particularly when it means bringing in hordes of expensive consultants who just drain the coffers for little benefit.

Third, going for the big donor cash means foreclosing alternative sources of money and significant enthusiasm. Small donors in large numbers can add up to sums that compete with or even exceed the big donor haul, and dedicated volunteers can make up for a lot of expensive ads through individual canvassing. But such people are not going to pony up or volunteer nearly so much for someone raking in corporate cash by the boatload. A reputation for integrity is a valuable political asset to cultivate — but one easy to the perception of taking bribes.

Finally, taking big donor cash is unpopular in itself. Consistently around two-thirds of voters say corporations have too much influence in society, while 84 percent say there is too much money in politics. Conversely, one of Bernie Sanders' most popular stances was his refusal to take money from corporations or the ultra-rich.

All these factors came together in the shocking upset victory of Alexandria Ocasio-Cortez in the Democratic primary in New York's 14th district. She was outspent 10-1 (her opponent was one of the biggest corporate stooges in politics), but still raised a goodly sum through small donors. Her policy literature was bold, clear stuff like Medicare for all and tuition-free college — stuff to enrage the Michael Bloombergs of the world. She released some excellent posters and ads — made at a steep discount by lefty artistic types enthused by her campaign message.

That was a deep-blue district, to be sure — but also a congressional primary campaign, where money should matter a lot more than races further up the food chain.

Democrats should take notice, and stop assuming that being a big money sellout is a guaranteed political winner.