Billionaire Michael Bloomberg’s presidential campaign has spent more on digital advertising campaigns with Google and YouTube in the last month than President Donald Trump’s re-election campaign has spent in the last year, according to a report.

The New York Times reports:

[Bloomberg’s] effort, which is targeting seven battleground states where polls show Mr. Trump is likely to be competitive in November, is just one piece of an advertising campaign that is unrivaled in scope and scale. On Facebook and Google alone, where Mr. Bloomberg is most focused on attacking the president, he has spent $18 million on ads over the last month, according to Acronym, a digital messaging firm that works with Democrats.

That is on top of the $128 million the Bloomberg campaign has spent on television ads, according to Advertising Analytics, an independent firm, which projects that Mr. Bloomberg is likely to spend a combined $300 million to $400 million on advertising across all media before the Super Tuesday primaries in early March.

Bloomberg’s fledgling campaign has now spent more on Google and YouTube in the past month than the Trump campaign has spent all year.

The former New York City mayor’s outsized spending has received scorn from several of his fellow White House contenders, including Sens. Bernie Sanders (I-VT) and Elizabeth Warren (D-MA).

“I’m disgusted by the idea that Michael Bloomberg or any other billionaire thinks they can circumvent the political process and spend tens of millions of dollars to buy our elections,” Sanders said last month of Bloomberg’s ad blitz.

“If you can’t build grassroots support for your candidacy, you have no business running for president,” he added. “The American people are sick and tired of the power of billionaires, and I suspect they won’t react well to someone trying to buy an election.”

During a recent campaign event in Ankeny, Iowa, Warren accused Bloomberg of attempting to “buy” the Democrat nomination.

“I am here on day two of Michael Bloomberg’s $37 million ad buy,” Warren said. “Michael Bloomberg is making a bet about democracy in 2020 — he doesn’t need people, he only needs bags and bags of money. I think Michael Bloomberg is wrong and that’s what we need to prove in this election.”

“Think about it this way, his view is he doesn’t need people who knock on doors, he doesn’t need to get out and campaign with people, he doesn’t need volunteers, and if you get out and knock on 1,000 doors, he’ll just spend another 37 million dollars to flood the airwaves, and that’s how he plans to buy the nomination in a Democratic Party,” she added.

Despite Bloomberg spendings tens of millions of dollars, recent polls show support for his bid for the White House has grown only marginally. A Reuters/Ipsos survey conducted between December 18 and 19, shows roughly 5 percent of Democrat voters back Bloomberg, a meager increase from 3% in November. The same poll shows former Vice President Joe Biden at 18 percent, Sanders at 15 percent and 10 percent for Warren.

Bloomberg was forced to apologize following a report revealing his campaign indirectly used prison labor to make telephone calls. The campaign claimed it did not know prisoners were being used to make the calls and terminated its agreement with ProCom, a New Jersey-based call center company.

“We didn’t know about this and we never would have allowed it if we had,” Bloomberg spokesperson Julie Wood told The Intercept, the news outlet which broke the story. “We don’t believe in this practice and we’ve now ended our relationship with the subcontractor in question.”