WASHINGTON (Reuters) - Democratic U.S. presidential candidate Mike Bloomberg has hired about 800 staff members as part of a plan to compete in the 14 states that hold Super Tuesday primary contests on March 3, his campaign said on Monday.

FILE PHOTO: Democratic presidential candidate Mike Bloomberg opens his Tennessee 2020 campaign headquarters in Nashville, Tennessee, U.S. December 19, 2019. REUTERS/Harrison McClary

The media billionaire and former New York mayor has used his personal fortune to quickly build a national campaign since joining the presidential race in November - many months after Democratic Party front-runners started campaigning.

He trails leading Democrats Joe Biden, Elizabeth Warren and Bernie Sanders in public opinion polls as they seek to challenge Republican President Donald Trump in the November 2020 election.

But Bloomberg’s staffing levels gives his campaign a sizable nationwide presence. The campaign for Biden, a former U.S. vice president who leads the Democratic contest in many polls, said it has more than 400 staff members across the country.

Bloomberg’s hires reflect an unorthodox, risky strategy of focusing on the Democratic nominating contests in March and skipping the important first matchup - the Iowa caucuses on Feb. 3 - as well as key primaries in New Hampshire, Nevada and South Carolina.

He has hired about 500 staff members in more than 30 states, in addition to about 300 at his New York campaign headquarters, a campaign spokeswoman said.

The campaign did not disclose state-by-state staffing tallies, but the organization’s states director, Dan Kanninen, said there were staff “on the ground in every Super Tuesday” contest.

“We will compete everywhere,” said Kanninen. “Our campaign is building the most robust national organization and infrastructure to beat Donald Trump.”

The candidate opened his second California field office in central Los Angeles on Monday.

The size of Bloomberg’s nationwide campaign staff was first reported by NBC News.

Bloomberg is also using his estimated $53 billion fortune to fund a massive advertising campaign that has prompted criticism from other candidates, including progressives Warren and Sanders, that Bloomberg is trying to buy the U.S. election.

Bloomberg, who is campaigning as a centrist Democrat, spent more than $76 million on television ads between mid-November and mid-December, more than all other presidential candidates put together, according to the Wesleyan Media Project.

His spending includes ad buys in delegate-rich Super Tuesday states like California and Texas, as well as in Florida, Illinois and Arizona, which won’t hold contests until March 17.

Bloomberg has proposed creating a public health-insurance option, banning assault weapons and slashing U.S. carbon emissions - ideas that resemble those of fellow centrists Biden and Pete Buttigieg, the former mayor of South Bend, Indiana.

Speaking to supporters at his new Los Angeles field office, Bloomberg reminded his audience that more delegates are up for grabs in California than any other state in the nominating contest.

“I’m running to defeat Donald Trump,” he said.