WASHINGTON — Senator Bernie Sanders often complains that people make too much of the “democratic socialist” label he gives himself.
But now, after eight years in the Senate in which he has sometimes been seen as a New England gadfly, the Vermonter is assuming a new, prominent role that puts him squarely in the center of many debates about the role of government in American life.
Sanders, an independent who caucuses with Democrats, became the ranking minority member on the Senate Budget Committee when Congress returned to begin a new session.
That will make him a leading voice for Democrats as they clash with Republicans, who now control the chamber, over government spending, entitlement reform, and taxes.
At the same time, the man who sometimes can make Senator Elizabeth Warren of Massachusetts look like a conservative is contemplating a long-shot run for president, either as an independent or Democrat, in an attempt to amplify his voice even more.
“Media gets hyped up about the word,” the 73-year-old Sanders said in an interview, referring to socialism, “but most important is what we stand for.”
And what exactly does he stand for? Mostly, it’s fighting against things he finds “absurd” or “totally absurd.”
“We have some of the largest and most profitable corporations in America paying zero federal [income] tax now and that’s totally absurd,” he said, adding, “Right now you have, clearly, an absurd and complicated tax code which benefits the wealthy and large corporations.”
Hedge fund managers pay a lower effective tax rate than truck drivers or teachers, he complained during another point in a 20-minute interview. “That’s absurd!”
The federal budget, the focus of the committee on which Sanders will sit, has been a major flashpoint. Democrats and Republicans have clashed over the size of government as well as on health care policy, financial reform, and a variety of other issues.
Failure to reach a spending agreement in 2013 led to a 16-day government shutdown. The budget deficit, projected at $469 billion for the 2015 fiscal year, has been in decline but remains one of the most politically divisive topics.
The budget committee sets broad parameters on spending and taxing, while two other committees, appropriations and finance, are responsible for the specifics on which programs get funded and how the tax code is written.
Sanders has a long list of budget priorities. He advocates an expansion of Social Security and has clashed with President Obama over cuts to entitlements. He said he will push Obama to use the threat of a veto to draw sharp lines with Republicans. He said he would push to increase spending on infrastructure and vigorously resist any cuts to social programs.
Sanders, born and raised in Brooklyn, rose to prominence when he won an unlikely bid to be mayor of Burlington, Vt., in 1980, also as a socialist, prompting sales of T-shirts with the slogan, “Welcome to the People’s Republic of Burlington.”
First elected to the House in 1990, he is now the longest-serving independent member of Congress in American history, according to his office. He has built a following among liberals and won broader praise for his recent effort in steering the Veterans Affairs Committee.
Sanders won his new role on the budget committee because four other senators with more seniority turned it down to become the ranking members of different committees.
His ascendancy is one of several recent signs of Democrats’ leftward shift. Senator Orrin Hatch of Utah, the longest-serving Republican in the Senate, noted as much in a recent interview with the Globe, conducted just after Warren led a fight over financial regulations that pitted her against Obama.
“She is one of the icons of the left, and the Democrats have pretty much all turned left,” he said.
Sanders, despite strong stands on spending, taxes, and entitlements, said he believes he can compromise with Republicans on trans-portation spending. He also had success last year, while leading the Veterans Affairs Committee, in passing a bipartisan bill designed to fix flaws in the health care system that serves veterans.
The Republican who will lead the budget committee is a staunch conservative, Senator Mike Enzi of Wyoming.
But in a statement to the Globe, Enzi stressed that he worked successfully in the past the late Senator Edward M. Kennedy. Enzi, who was the top Republican on the health committee during part of Kennedy’s tenure as the Democrats’ leader, said that both men tried to find common ground on the 80 percent of issues on which they agreed.
Enzi “looks forward to having robust conversations with Senator Sanders about addressing America’s fiscal problems and plotting a course out of our $18 trillion national debt,” his office said.
Don Stewart, a spokesman for the incoming majority leader, Mitch McConnell of Kentucky, said in an e-mail that it’s “a decision that Dems made to make [Sanders] the face of their budget process,” but deferred to Democrats to offer opinions on the larger meaning.
Senator Charles E. Schumer, the third-ranking Democrat in the Senate who helps chart the party’s political strategy, had only kind words for Sanders in an e-mail sent by his office.
He called Sanders “among the most principled members of the Senate” and pointed to his work passing the Veterans Administration bill.
“Those are exactly the qualities you want in a ranking member,” he said.
Still, there remain many reasons for skepticism, given the recent record of dysfunction in Congress that has resulted in numerous showdowns over budget issues.
“If you are actually setting fiscal policy for the future, it is a very unpleasant thing to talk about either tax increases or spending increases,” said G. William Hoagland, a budget hawk who is senior vice president for the Bipartisan Policy Center, a centrist think tank.
Hoagland said he has talked to a couple of Democratic senators, whom he would not name, who are wary of making Sanders a prominent voice on the budget.
Hoagland said he believes moderate Democrats on the committee — including Mark Warner and Tim Kaine of Virginia and Angus King, a Maine independent who caucuses with Democrats — will prevent Sanders from taking too hard a line.