Money might be hard to come by in many parts of America, but it’s cheap in the 2016 election. Wealthy Republican donors have given nearly $400 million so far to presidential candidates with zilch to show for their efforts, including at least $63 million donated to super PACs supporting the latest GOP dropout – Sen. Ted Cruz.

Cruz quit the race after losing the Indiana primary election to Donald Trump, who has nearly locked up the GOP presidential nomination. With nine primary contests left, Trump now seems all but certain to win enough delegates outright to clinch the nomination, leaving no path for rivals.

At this point, it’s no longer surprising that Trump is trouncing opponents. What is surprising, however, is the vast sum Trump foes have wasted trying to steer the nomination toward anybody other than Trump. Yahoo Finance has been tallying the millions spent in futility on this year’s presidential campaign, and the total spent on super PACs supporting losing Republican candidates now totals roughly $375 million. That’s more than Mitt Romney’s entire estimated net worth. It’s equivalent to two years’ worth of profits for Netflix.

Cruz enjoyed the support of a small number of rich donors willing to commit large amounts of money to his cause. New York hedge-fund manger Robert Mercer of Renaissance Technologies donated at least $13 million to a Cruz super PAC, allowed to accept unlimited donations, called Keep the Promise I. Toby Neugebauer, a Texas energy investor and son of a member of Congress, gave another $10 million to a second super PAC called Keep the Promise II.

The third Cruz super PAC, Keep the Promise III, collected $15 million from two Texas brothers, Dan and Farris Wilks, who became billionaires after they sold a fracking operation in 2011. Including the contributions of smaller donors, those three promise-keeping super PACs raised more than $41 million for Cruz.

A fourth Cruz super PAC, Stand for Truth, raised another $11 million. That super PAC had no eight-figure donors, but federal records show that Adam Roos, CEO of Goldcrest Investments in Dallas, gave $1 million, as did Gale Alger of Palm Beach, Fla., and a Houston company called Trinity Equity Partners. Other donors gave as much as $325,000 each. Much of the money was used running ads against Marco Rubio and Donald Trump. Smaller contrubitions from other donors pushed total funding for Cruz super PACs to $63 million.

As of the end of March, the super PACs supporting Cruz had spent about $42 million of the $63 million they raised, and it's likely they spent more in April as Cruz made his final stand against Trump. Still, there may be some money left to return to donors or pass on to other political groups. Interestingly, Keep the Promise II, funded entirely by Neugebauer, had almost all of its cash on hand as of March 31, suggesting some sort of deal between the donor and the candidate; Neuegbauer may have insisted, for instance, that the money be spent only on the general election.