Senate Democrats just won subpoena power. That includes Elizabeth Warren.

Massachusetts Senators Ed Markey and Elizabeth Warren could both see benefits with a 51-seat majority in the Senate.SAUL LOEB/AFP via Getty Images

WASHINGTON — Senator Raphael Warnock’s victory in the Georgia runoff cemented the Democrats’ 51st seat in the Senate but delivers a lot more than just a one-vote cushion.

The shift from a 50-seat majority to 51, while seemingly insignificant, opens up a whole range of possibilities to exercise oversight authority — especially for watchdog-minded senators such as the two Democrats from Massachusetts.

“It makes all the difference in the world,” said Connecticut Senator Richard Blumenthal, a Democrat.

Democrats currently have a majority by virtue of Vice President Kamala Harris’s tie-breaking vote But day to day, the Senate operates under a power-sharing agreement, meaning committee membership is evenly split. This requires Democrats to seek consensus or time-consuming floor procedures to advance any business that doesn’t receive bipartisan support.

Now, with Warnock’s victory over Republican Herschel Walker, Democrats will fully control committees when the new Senate gavels in next year, allowing them to set hearings, call witnesses, advance nominees, and even issue subpoenas without needing Republican approval.

The expanded authorities will allow Democrats to investigate a range of targets — powers that could be useful for Senators Elizabeth Warren and Ed Markey, both of whom harbor deep skepticism about private sector practices and who don’t hesitate to go toe-to-toe with corporate CEOs.

That could mean close scrutiny of a range of hot-button issues currently simmering on the sidelines, including antitrust concerns with big tech companies, stewardship of privacy online, the role and regulation of cryptocurrency, and China’s influence in the United States and international trade.

Neither senator was willing to talk about their specific plans in the days before the runoff in Georgia concluded, saying they’re focused on the upcoming lame duck session in Congress. But both also acknowledged that the outright majority will bring many new tools to their disposal.

“You know, we’ll see,” Warren said with a smile in an interview. “Let’s see who’s doing what by the time it’s January.”

Markey conceded that a true majority will at least streamline their work.

“When there’s a majority that the Democrats have, it’s going to make it much easier to have the witnesses, the hearings, the framing of the issues, you know, that are important for the American people to hear,” he said.

Warren and Markey chair several subcommittees, giving them and other Democrats numerous possibilities for investigations and private sector scrutiny. Warren chairs the economic policy panel of the banking committee and the Fiscal Responsibility and Economic Growth Subcommittee on the finance committee, giving her oversight of monetary policy, pricing issues, and competition. Markey can scrutinize climate issues and foreign policy through his positions as chair of the panel on Clean Air, Climate and Nuclear Safety under the Environment and Public Works Committee and the East Asia, the Pacific, and International Cybersecurity Policy Subcommittee under Foreign Relations.

To be sure, the Senate as an institution tends to be more cautious and slow-moving than the House. Subpoenas, which are usually issued as a last resort to compel witness cooperation or produce documents, are rare in the upper chamber and tend to require a laborious process for approval. But the mere knowledge that Democrats have the ability to call hearings and issue subpoenas in extreme cases may make targets of their scrutiny more inclined to participate. Warren is a prolific letter writer, signing on or authoring more than 100 requests for answers or urging policy changes this year alone, an average of more than two per week.

“I, for one, am not convinced that Democrats are going to try and emulate the House and just start sending subpoenas willy-nilly,” said Jim Manley, a former aide to the late Senators Harry Reid of Nevada and Edward M. Kennedy of Massachusetts. “Most of the chairmen of the committees are pretty cautious by nature. . . . Sometimes I wish Senate Democrats would be as aggressive as some of the folks are in the House.”

No senators questioned by the Globe were eager to talk about subpoena power. On the campaign trail, Warnock repeatedly sidestepped questions about the difference that his election would make for Democrats in Washington.

“I know folks are doing all the other calculations and that’s fine. But this really is about who’s going to represent Georgia, this state,” Warnock said on Tuesday.

When pressed specifically on the question of subpoena power last Sunday at a campaign event, Warnock directed the question to his fellow Senate Democrat and campaign trail companion, Jon Ossoff of Georgia, who chairs the Senate’s Permanent Subcommittee on Investigations and is not on the ballot this year. But even he downplayed the significance.

“We have undertaken substantive oversight — for example of conditions in prisons, jails, and detention facilities across the country — this last year in the Senate as presently composed,” Ossoff said. “My view is this election is less about the national balance of power.”

Blumenthal noted that having streamlined authority on his top post, the Judiciary Committee, could mean significantly more judges are confirmed, since members won’t have to worry about tie votes to advance nominees prolonging the process. Independent Vermont Senator Bernie Sanders, who chairs the Budget Committee, said the majority control of panels would make it easier to get work done. Senator Sherrod Brown of Ohio, who chairs the Banking Committee, said the 50-50 majority made the Senate “less nimble.”

Warren said she is interested in financial services, pointing to results her scrutiny of big business, such as that of payment app Zelle that she investigated for rising fraud, has already achieved. Markey, who spent decades in the House, is also oversight minded, recently picking a fight on Twitter with Elon Musk over the billionaire’s purchase of the social media company and handling of its verification program.

But even as Democrats remain coy about their future plans, outside watchdog groups are waiting to see what a more empowered majority will yield.

“The Senate is notoriously more constrained than the House in terms of using its oversight authority, but even without a gavel, Senator Warren has proven to be dogged and creative in doing oversight from her personal office,” said Donald K. Sherman, a former top Senate and House oversight aide now at the nonprofit watchdog Citizens for Responsibility and Ethics in Washington. “I have every confidence that Senator Warren will find very productive ways to use her expanded oversight capacity.”

Sherman said other senators have already followed Warren’s model, and he hopes that continues. With the House flipping hands, he said, Democratic senators will have an opportunity to pick up investigative threads started by their House colleagues who are now losing control of committees.

And at least one senator said he is looking forward to the 51-seat majority, if only for the pressure it takes off of him as the often-elusive 50th vote for Democrats to get something passed.

“It would make it easier for me,” said West Virginia Senator Joe Manchin.