Bolstered by endorsements from his one-time Democratic rivals and a decisive win in South Carolina, Joe Biden heads into Super Tuesday with a newly energized campaign that will try to prevent front-runner Sen. Bernie Sanders from taking command of the 2020 race.

The 14 states going to the ballots on Super Tuesday stretch across the nation — from Maine to California — and hold one-third of the 1,991 delegates needed for a candidate to be nominated at the Democratic National Convention in July.

Going into Tuesday’s contests, Sanders has an edge over Biden in the delegate count — 60 to 54 — following his strong showing in the Iowa caucuses, New Hampshire and Nevada.

But with wins in delegate-rich California, where Sanders is leading the Democratic field by double-digit margins, and Texas, the Democratic socialist from Vermont could build an insurmountable delegate lead.

At a rally in Minnesota on Monday evening, Sanders called on supporters of Pete Buttigieg and Sen. Amy Klobuchar, who endorsed Biden on Monday, to join his campaign.

“To all of Amy and Pete’s millions of supporters, the door is open. Come on in,” Sanders said. “We all share the understanding that together we are going to beat Donald Trump.”

Biden, with the support of Buttigieg and Klobuchar, is hoping to consolidate moderate Democrats against Sanders’ progressive policies.

At a rally in Dallas, Biden pitched himself to the crowd as a uniter who would return civility and credibility to the White House after defeating Trump.

“My message to everyone, every person who’s been knocked down, counted out, left behind: This is your campaign. We need you. We want you, and there’s a place in this campaign for you. So join us,” he said.

Super Tuesday also marks the first time former New York Mayor Mike Bloomberg is on the ballot.

The billionaire media mogul sat out the first four contests, betting his nationwide advertising blitz, into which he sank more than $500 million of his own fortune, would propel him to the Democratic nomination.

“I’ve won three elections so far and I don’t plan on losing now,” Bloomberg told a rally Monday in Virginia.

The three-term mayor’s national poll numbers slipped after a poor performance at his first Democratic debate, but have picked up recently to put him around 15 percent — behind Biden and Sanders but ahead of Sen. Elizabeth Warren.

Warren of Massachusetts, which is one of the Super Tuesday states, set herself up as an alternate choice to Biden the insider and Sanders the outsider.

“Voters deserve a choice of someone with unshakable values who can also get things done, and bring all kinds of Democrats along with her,” she said Monday in Los Angeles.

“Voters deserve a choice of someone who can both do the work to transform our government from the inside and who can bring pressure to bear on government by leading a grassroots movement from the outside,” she said.

Rounding out the Democratic hopefuls is Rep. Tulsi Gabbard of Hawaii.

Gabbard hasn’t won any delegates in the first four contests and is polling at about 1 percent.

With Post wires