Hillary Clinton is getting off her back foot after a clumsy start to her presidential campaign.

After being buffeted for months by the controversy over her emails, and seeing her dominance in the polls decline, Clinton has made aggressive moves to shore up her support on the left and take the fight to the Republican field.

A strong performance on the debate stage during the first Democratic clash, set for Las Vegas on Tuesday night, could help the former secretary of State maintain her altitude, quiet talk of a White House bid by Vice President Biden and slow the rise of her main rival, Sen. Bernie Sanders.

“We’ve seen all email, all the time,” said David Birdsell, a debate expert at Baruch College in New York. “This is the first sustained encounter with her in which voters will have the opportunity to hear about something else.”

Clinton has been trying to change the subject recently, with some success.

Her announcement last week that she opposed the trade agreement known as the Trans Pacific Partnership, or TPP, came as a welcome development to liberals who have been skeptical of her candidacy.

She also seized the initiative on gun control, perhaps the one issue in which she can convincingly run to Sanders’ left, after a mass shooting in Oregon.

On Friday, Clinton met with activists from the #BlackLivesMatter movement — a constituency that has given Sanders considerable trouble — later tweeting that “Racism is America’s original sin.”

And Clinton has even sought to turn the Benghazi probe to her advantage.

Her campaign pounced last week after House Majority Leader Kevin McCarthy (R-Calif.) appeared to suggest that the House panel investigating the 2012 attacks deserved credit for lowering Clinton’s poll numbers.

In response, the Clinton campaign response released a 30-second TV ad, beginning with the words, “The Republicans finally admit it.”

Jennifer Lawless, the director of the Women and Politics Institute at American University, cautioned that Clinton’s email saga is by no means over. But the Democratic frontrunner could at least calm things down with a strong debate performance, she said.

“I think it is premature to say that those kinds of allegations and quote-unquote ‘scandals’ are behind her. It’s unclear,” said Lawless. But, in Las Vegas, Clinton could “stand out as the clear and obvious leader on the stage. She needs to demonstrate that she is presidential and the other candidates are not ready for prime-time.”

The positive stretch for Clinton has not erased the concerns that many Democrats have about her campaign, however. Some of them worry that the habits of defensiveness and evasiveness often cited by her critics will creep into her answers at the debate.

“The concerns that voters have, she has got to hit them head-on,” said one Democratic strategist, speaking on the condition of anonymity. “My take would be, don’t wait for questions about emails and TPP. You have to come out and hit those from the start. But my strong suspicion is that she won’t do that. My guess would be that they are going into the debate thinking, ‘There is nothing to be gained by taking any risks.’ ”

Any questions Clinton receives on TPP are almost certain to focus on how she has now come to oppose a trade deal that she once called a “gold standard.” Some independent observers believe that the Clinton campaign might judge accusations of flip-flopping to be less important than moving to the left to limit her vulnerability to the Sanders challenge.

Cal Jillson, a professor of political science at Southern Methodist University, asserted that, in the wake of the damage inflicted by the email controversy, the Clinton campaign appears to have “decided in the run-up to the first debate that they need to get right with the Democratic base.”

He added: “She is willing to take the charge that she is changing positions because I think she really does feel the need to take the few opportunities she has to get to the left of Bernie Sanders and to assure the Democratic grassroots that she is their candidate.”

On gun control, Clinton floated the idea last week of using executive order, as president, to expand background checks. That, in turn, prompted some media attention on Sanders’ past support for pro-gun positions, including his vote to block class-action lawsuits against gun manufacturers while a House member.

Still, most observers think the real challenge for Sanders come Tuesday evening will be less about proving his unyielding fealty to progressive policies and more about presenting himself as a plausible general election candidate.

“He needs to continue to suggest to more moderate Democrats that he deserves another look, that he is not too far to the left to represent the party,” Jillson said.

“He has a fairly daunting burden of proof to suggest that a lot of things that he’s suggesting can actually become law,” Birdsell said.

The lion’s share of the attention in Las Vegas will be commanded by Clinton and Sanders, but three other Democratic candidates will also be on the stage: former Maryland Gov. Martin O’Malley, former Sen. Jim Webb (D-Va.) and former Rhode Island Gov. Lincoln Chafee.

All three are struggling badly in the polls, but that could make them more likely to throw verbal bombs in order to command attention.

“I think the ones to watch are Martin O’Malley and Webb because I think both of them are likely to take a harder approach to Hillary,” said the Democratic strategist.

“That to me is the big question: Does anyone really challenge her directly?”