Richard L. Hasen is Chancellor's Professor of Law and Political Science at UC Irvine School of Law and author of Plutocrats United: Campaign Money, the Supreme Court, and the Distortion of American Elections . The opinions expressed in this commentary are his.

After all, the shock-and-awe campaign of Jeb Bush's Super PAC, with its nine-figure budget , was far less than awesome. Bernie Sanders raised tens of millions of dollars in very small donations (recall his constant refrain that the average donation he received was $27 ).

And Donald Trump's major selling point was that he was self-funding his campaign (which was not really true ) and too rich to be bought anyway, leaving big donors on the sidelines. (Never mind that he still relied on big money in the primaries -- his own.)

But now comes the news of Trump's embarrassingly paltry fundraising numbers for May, in which he has less cash on hand than many congressional and local candidates, and only one-fortieth of Hillary Clinton's cash on hand.

It looks like big money still matters a lot, as Trump may find out the hard way.

We've already seen in the primaries that money cannot make up for otherwise troubled candidacies and that candidates without big money can run somewhat competitive campaigns if they have mass support. The fiasco of Jeb Bush's campaign illustrates that even with tons of money, advertising cannot get the public to buy a product it doesn't want.

And the Sanders campaign shows that it is possible to run a grassroots campaign for a primary without relying on a Super PAC or the kind of traditional bundling that major party candidates have tried. Sanders lost because voters preferred Clinton, not because he was outgunned on the money front -- at some points in the campaign, he was even spending more than Clinton. Thousands of small donations made Sanders competitive for months. Had voters preferred him, we could have tested whether it would be possible to run a mass-based general election campaign without reliance on big money. Right now that is a question mark.

Trump's primary campaign relied mainly on personal loans of millions of dollars and free publicity. Already high in name recognition, and prone to outrageous statements, Trump got a huge amount of free media exposure -- one study estimated it to be worth $2 billion. By cranking up the outrage and appealing to the Republican base, Trump was able to succeed in the primaries despite being outspent by rivals.

JUST WATCHED Clinton tries to attack Trump on his campaign strength Replay More Videos ... MUST WATCH Clinton tries to attack Trump on his campaign strength 03:37

Now that we are entering the general election, it is clear that Trump can use neither outrage nor self-funding to propel himself into competition with Hillary Clinton. Either Trump is not as rich as he says he is , or he is too cheap to cough up the hundreds of millions of dollars (minimally) it would take to be competitive with Clinton.

While outrage appeals to the Republican primary base, Trump's campaign seems to be turning off huge contingents of voters his campaign will need to put together an Electoral College victory.

JUST WATCHED Trump campaign spend 17% of cash on Trump entities Replay More Videos ... MUST WATCH Trump campaign spend 17% of cash on Trump entities 04:03

Trump's poor fundraising, if it continues over the next few months, is likely to cost him dearly in two ways.

First, Trump is unlikely to be able to run advertising and build the kind of field operations in battleground states necessary to register voters and get out the vote. Usually major party candidates and allied campaigns are pretty evenly matched financially, making the role of money in presidential elections something of a wash. If Clinton's side vastly outspends Trump's side, it could well have big effects on election results -- especially if Clinton's campaign uses resources on advertising to keep Trump's negatives up.

Trump's lack of fundraising effectiveness also shows the failure of his management style. If a candidate cannot pick the right people to manage a successful campaign for president, it signals the candidate might not be able to pick the right people to manage the U.S. government. The fundraising missteps reinforce the already-visible image of a Trump management problem. His firing of his campaign manager on a Monday morning , when he could have campaigned on the FBI's fumbling of the release of the Omar Mateen transcripts , was amateurish.

Trump's fundraising failures thus far may signal to the biggest Republican donors that his campaign is a lost cause, and that the best way to hedge against a likely Clinton presidency is to pour money into close Senate races. Wealthy donors may find it more effective to throw millions into Super PACs in competitive Senate and House races rather than at a presidential campaign that doesn't seem to have its act together.

Even if big donors' money can't control Congress or buy election outcomes outright, it does open many doors for them once lawmakers are elected. It affects what Congress does and does not do.

As it turns out, big money still matters even in the oddest presidential election of our lifetimes. Even -- or especially -- when one of the candidates is an alleged billionaire.