In the final three months of 2015, the former reality television star raised just $2.64 million for his presidential campaign, a $1.17 million decline from the third quarter, when he took in $3.18 million. For perspective, Jeb Bush—who polls behind Trump, Ted Cruz, Marco Rubio, and Ben Carson, and whom Trump has called “dumb as a rock”—managed to raise $7 million in the same time period.

The erstwhile Republican frontrunner may not exclusively rely on his grassroots donors to power his vanity project of a campaign, but the money donated to him is a good bar by which to measure how solid his support is. A crowd of 20,000 coming out to see him in Biloxi, Mississippi, could mean anything. It could mean those 20,000 people love him and will vote for him, or it could mean he was the most interesting show playing that night. But money is different. Most people don’t have enough of it to send it to someone they don’t believe in.

Trump’s financial slump began in the lead-up to the Iowa caucuses, where he lost on Monday night, coming in second place to Cruz, despite holding an almost consistent lead in the polls for months. In hindsight, signs of Trump’s impending failure could be gleaned in his collapsing grassroots support, evident in the fundraising numbers, as well as in his weak ground game in the Hawkeye State.