Sanders plans to release a statement Thursday confirming that he'll seek the presidency in 2016, Kinzel reported. He'll hold a formal campaign announcement in Vermont "several weeks" later.
Spokesman Michael Briggs would neither confirm nor deny the report Tuesday afternoon. He noted that Sanders has previously said he would reveal his intentions by the end of the month.
"We'll have something to say later this week," Briggs said.
Sanders, the nation's longest serving independent in Congress, would face off against former secretary of state Hillary Clinton, who announced her candidacy two weeks ago.
Sanders has made repeated visits to early presidential primary and caucus this year, touching down in Iowa, New Hampshire, Nevada and South Carolina, among others. While he acknowledged he was weighing a potential campaign, he repeatedly put off an announcement. Throughout last year, he had indicated he would decide whether to run after November's midterm elections. In December 2014, he said he would decide by March.
Sanders has repeatedly said that he would not run for president merely to highlight issues — namely, income inequality — that Vermonters have heard him discuss for decades.
“The decision that I’m going to have to reach is whether there is that willingness to stand up and fight back,” he said during an appearance at the Brookings Institution in Washington, D.C., in February. “And if there’s not, I don’t want to run a futile campaign. If I run, I want to run to win. To run to win, we need millions of people actively involved.”
He has also said that he would not seek to tarnish Clinton's reputation in the primary.
“It is not my style to trash people,” he told the Brookings Institution crowd. “It is not my style to run ugly, negative ads. If I run and if Secretary Clinton runs, what I would hope would happen is that we would have a real, serious debate. This is a woman I respect — clearly a very intelligent person who I think is interested in issues, by the way.”
The announcement will represent the pinnacle, to date, of a most unlikely political career. Born to Polish immigrants in Brooklyn — a borough that gave him a thick accent that remains undiminished — Sanders began his political career in the Green Mountain State in January 1972. He garnered 2 percent of the vote in a special election to replace the late U.S. Senator Winston Prouty.
Throughout the 1970s, running as a Liberty Union candidate, Sanders lost senate and gubernatorial races, never cracking double digits on Election Day.
In 1981, he ran for mayor of Burlington as an independent and stunned the city’s political establishment by unseating a six-term Democratic incumbent. During four terms leading Vermont’s largest city, Sanders drew progressive thinkers from across the country to help run Burlington City Hall.
But his ambitions for higher office never waned. In 1986, he lost a race for governor for a third time. In 1988, he lost a race for a seat in the U.S. House. Finally, in 1990, Sanders secured a seat in Congress, beating Republican Peter Smith. (He owed much of the victory to the National Rifle Association, which targeted Smith for defeat after he backed a ban on semi-automatic assault rifles.)
In Washington D.C., Sanders immediately staked out liberal turf. He founded the Congressional Progressive Caucus, which now claims dozen of members, and was one of just six members of the House to vote against the first Iraq war. (He also opposed the 2003 Iraq invasion.) He was against the North American Free Trade Agreement in 1993.
In 2005, after Jim Jeffords announced he would not seek re-election, Sanders announced he would seek Jeffords’ seat in the U.S. Senate. He soundly beat Republican Rich Tarrant in the most expensive political race in Vermont history, and cruised to re-election in 2012.