Former New York City Mayor Michael Bloomberg is now in fourth place among Democrat presidential primary candidates, according to a national poll released Wednesday.

The Monmouth University survey shows Bloomberg has nine percent support nationwide with Democratic voters — a four percent increase since respondents were asked about the candidate in December. The same poll found former Vice President Joe Biden is respondents’ top choice with 30 percent approval, while Sen. Bernie Sanders (I-VT) placed second with 23 percent — a rise of two percent. Sen. Elizabeth Warren (D-MA) fell 3 percent to 14 percent, putting her in third place, and former South Bend, Indiana, Mayor Pete Buttigieg placed fifth with 8 percent.

“With the exception of Bloomberg’s entry, this race looks pretty much like it did six months ago,” Patrick Murray, head of the Monmouth University Polling Institute, said in a statement. “But that stability masks the potential for sizable swings once the first contests are held. Iowa and New Hampshire will play a major role in shaping national voter preferences.”

The poll was undertaken via telephone between January 16-20 with 847 respondents. The survey has a margin of error of plus-or-minus 3.4 percentage points.

Earlier Wednesday, a CNN poll found Bloomberg placing fifth with five percent support, nationally.

Bloomberg’s bump in the polls come as he continues to pour tens of millions of dollars in advertisements. Since entering the race, he’s dropped nearly $250 million on television spots across the country. The move has met sharp rebuke from his rival, who say he’s attempting to buy the White House.

“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 recently said of Bloomberg’s massive ad buys. “If you can’t build grassroots support for your candidacy, you have no business running for president. 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.”

Warren has echoed Sanders’ criticism during several campaign stops in key primary states.

“I am here on day two of Michael Bloomberg’s $37 million ad buy,” Warren said in November before supporters in Ankeny, Iowa. “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.”

However, Bloomberg appears unfazed by the criticism, saying earlier this month that he’s dumping millions into his candidacy sole to defeat President Trump.

“Number one priority is to get rid of Donald Trump. I’m spending all my money to get rid of Trump. Do you want me to spend more or less? End of story,” the businessman told Reuters.