The first one-on-one debate between Bernie Sanders and Hillary Clinton was more heated at times, as the Democrats try to highlight the distinctions between their campaigns after ending in a virtual tie earlier this week in Iowa.

The former secretary of state tried hard to brand herself as more progressive than her competitor, saying in the first minutes of the debate, "A progressive is somebody who tries to make progress. That's what I intend to do." She questioned Sanders' ability to actually fulfill the liberal promises he's made, such as making public college and university tuition free and enacting single-payer universal healthcare.

For his part, the senator from Vermont continued to highlight his self-assigned position as the anti-establishment candidate, and doubled down on his push for campaign finance reform and breaking up Wall St.

"What we need to do is stand up to big-money interests. When we do that, we can transform America," he said, adding that he would tax Wall St. speculations to finance his tuition free education plan.

The Wall St. debate dominated the first hour of the debate. Sanders reiterated his favorite talking points about the billionaire class and corrupt corporate powers dominating American politics.

Clinton argued that focusing on Wall St. only addressed one part of the issues with corporate power. She went on the offensive early on in the discussion, calling Bernie's admonishment of polticians tied to Wall St. a veiled dig at her personally.

"It's time you end the artful smear you and your campaign have been carrying out in recent weeks," Clinton said.

The two exchanged blows on the topic with nary a comment from MSNBC moderators Rachel Maddow and Chuck Todd for nearly a half-hour, before Maddow interjected to take the program to commercial.

"Obviously we touched a nerve," Maddow joked.

Near the end of the Wall St. discussion, Todd echoed a question from Wednesday's Democratic Town Hall about whether or not Clinton is willing to make the transcripts of paid speeches she's given at Goldman Sachs and other corporations public. Quick to dismiss the issue, she responded, "I'll have to look into that."

When the discussion shifted to national security, Clinton had the clear edge. Sanders reasserted his stance that the war against the Islamic State should be waged by Muslim troops fighting to protect "the soul of Islam," and stressed the importance of working in a strong coalition. Clinton stressed her years of experience in the Situation Room, exercising judgment on dire security issues. At the same time, she insinuated her competitor was ill-equipped to jump into that role: "You have to be ready on day one."

"I fully, fully concede that Secretary Clinton, who was Secretary of State for four years, has more experience — that is not arguable — in foreign affairs," Sanders said. "But experience is not the only point. Judgement is."

When Todd asked Clinton why she thought Secretary of Defense Ash Carter recently called Russia the biggest threat to national security, the experienced politician managed artfully to dodge the question, instead proffering the importance of keeping NATO strong and focused.

On several other issues, Clinton emphasized her alliance with President Obama's policies, while Sanders took the more liberal stance. While Clinton expressed support for protecting the use of the death penalty in "particularly heinous crimes, like terrorism," she thinks this should be a power reserved for the federal government. Sanders was fully opposed, saying "In a world full of so much violence, I don't think government should be part of the killing."

When Todd asked Clinton if she'd return to supporting the Trans Pacific Partnership, or TPP, which she's distanced from herself during this campaign, she offered tempered support for trade deals in general but said she's concerned about the details, and won't back TPP as it currently stands.

Sanders argued that he supports "fair trade," not free trade, and that deals like TPP are a disservice to American workers.

"I don't want the American people to be competing [for jobs] against people working for 50 cents an hour," he said.

Immigration and race relations weren't major topics in this debate, suggesting the candidates narrowed their focus to match the concerns of New Hampshire — the site of the next primary — where 94 percent of the population is white.

When the moderators — in a rare speaking moment — brought up scandals that have emerged in each campaign, the candidates didn't take the bait. Sanders said he "refuses to politicize" Clinton's email scandal, adding that he holds the same sentiment he did in the first debate, when he famously declared that the "American people don't care about [her] damn emails." In turn, Clinton refused to comment when asked if she wanted to comment on missteps and rules broken by Sanders' campaign staffers.

Near the end of the debate, the two were asked about the results of Monday's Iowa caucuses, where Clinton was declared the winner after the votes revealed a virtual tie (49.8 percent to 49.6 percent). Moderators pointed out that the Des Moines Register had called for an audit of the results, but Sanders said regardless of a recount, the votes would come up "roughly even."

"Whatever they decide to do, it's fine," Clinton said, flashing a pleased smile.

Much like in the Iowa caucuses, it's difficult to determine who came out on top in this debate, and the answer probably depends on who you ask. According to Sanders, though, the voters of the Democratic party were the real winners.

"On our worst days, I think it's fair to say, we're 100 times better than any of the Republican candidates," he said of himself and his competitor.

The Democrats will compete in the New Hampshire primary on Feb. 9. Sanders currently holds a 2-to-1 lead there, according to a CNN/WMUR tracking poll.

Reach Executive Editor Sara Tiano here; follow her on Twitter here.