Donald Trump’s May fundraising totals are disastrously bad - The Washington Post
If I understand the article correctly, Trump raised $3 million in May compared to $27 million by Clinton.
I am guessing that part of it may be due to his followers still thinking he's going to be self funded all the way to the White House (which, of course, he is not going to reach.) They liked the idea of his being self funded - giving money would interfere with that.
What an amusing problem for the Republicans.