CHARLESTON, South Carolina — Young people worship her opponent; her husband is hitting the stump, but bringing some inauspicious headlines with him; and her campaign is turning increasingly aggressive against a challenger no one thought would be much of a threat just months ago. For Hillary Clinton, as a second sure-thing presidential bid looks increasingly imperiled in the homestretch to Iowa, 2016 is beginning to feel too much like 2008.

The situation is beginning to make people wonder if history is repeating itself, with just a different progressive insurgent blindsiding the former secretary of state’s Titanic campaign.

Clinton’s troubles, which have worried many of her supporters, come just as the Democrats prepare to face off Sunday night in their final debate before the Feb. 1 Iowa caucuses and for the first time in 2016. The debate, hosted by NBC News and YouTube, is expected to be the most contentious one yet as both the Sanders and Clinton campaigns have stepped up their volley of attacks on one another. Former Maryland Gov. Martin O’Malley will participate in the debate as well.

Related: How to Watch the NBCNews-YouTube Democratic Debate

Clinton insists she’s not nervous about her prospects despite tightening polls, but her campaign’s actions in the past two weeks speak louder than her words. After going months without mentioning opponent Bernie Sanders by name, her campaign has abruptly turned the firepower they once reserved for Republicans.

In contentious conference calls, on the stump, and in her increasingly frequent television interviews, the candidate and her staff have opened a sustained multi-front assault on Sanders, aimed at everything from taxes to his TV ads. While she’s yet to raise doubts about a potential President Bernie Sanders’ ability to answer a 3 a.m. phone call, that might not be far off at this rate.

Related: Clinton's Emails Give Glimpse Into a Candidate Often Under Pressure

In some ways, it does all seem eerily similar to 2008, when Clinton’s first presidential bid was derailed by Barack Obama, who put together a coalition very similar to the one Sanders is tapping into now in Iowa. “I’m getting a little PTSD on the whole Iowa thing,” one former Clinton operative told Politico.

But in many other ways, the late-breaking downturn in Hillary Clinton’s 2016 campaign is more unexpected than in 2008. Her national polling lead, which held steady for months, has dropped faster than it did eight years ago and with less warning.

And this campaign should have been easier than the first. As inevitable as Clinton’s candidacy was thought to be in 2008, it was seen as even more so this year. Whereas in 2008, heavyweight Democrats boosted Obama, in 2016 the party cleared the field for Clinton and rallied behind her.

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Whereas in 2008, Clinton’s team did not understand the Iowa caucus process, as she recently told the Des Moines Register, in 2016 she’s assembled a crack squad of the most experienced and well-respective operatives in the game, who made sure to let you know they had learned the lessons of Clinton’s first bid.

Related: Full Coverage of the 2016 Presidential Race

Whereas in 2008, Clinton had one critical weakness — her Iraq war vote — that she probably could have done nothing to fix, in 2016 she has no such obvious Achilles Heel. While the vote will always be part of her history, she’s apologized for it and other issues seem more pressing this year to the Democratic base.

Whereas in 2008, she had a fairly standard resume for a presidential candidate (minus her time as first lady), in 2016 she is one of the most qualified presidential candidates of recent memory by any objective measure, with four years as the nation’s top diplomat under belt.

Whereas in 2008, she faced off against a Murderers’ Row of the Democratic Party’s brightest stars, in 2016 her opponents were initially considered so weak that the most pressing concern was whether the process would look to much like a coronation.

What she would give to have that problem again. “The inevitable candidate for the Democratic nomination may not be so inevitable today,” Sanders said in Iowa Monday night at a candidate forum.

But fortunately for Clinton, there’s one other difference between 2016 and 2008 that could save her.

In taking on the thought-to-be invincible Clinton 2008, Barack Obama combined a rare political talent with a tactically brilliant campaign operation and, most relevant to the current campaign, a major demographic advantage as he ran to be the first black president.

Bernie Sanders, for all his tremendous success, is no Obama. When it comes to basic political skills, Sanders is idiosyncratic. He’s uncomfortable discussing issues outside his wheelhouse of economic fairness and income inequality, is difficult for campaign staff to manage, and looks nothing like the made-for-TV Obama.

Whereas Obama’s campaign forever revolutionized the way campaigns are run, Sanders’ has embraced its rag-tag image. The campaign, savvy as it can be, often seems to be moving in different directions at once, with top aides contradicting each other and even the candidate himself.

Related: The Democratic Race: How We Got Here

And yet, none of that seems to matter so far. Sanders has defied the odds and put up a real challenge to Clinton precisely because he refuses to play the game the way it’s supposed to be played.

The good news for Clinton is that Sanders, a 74-year-old white man, lacks that third Obama quality.

Iowa was critical to Obama not just for the normal reasons Iowa is important to any candidate, but because he leveraged it unlock a a crucial bloc of voters. For black voters skeptical that Obama could actually win, Iowa was a test case. Once he won the state, which is 92 percent white, it proved that he could win over white voters, and thus maybe the entire country.

After that win, African-Americans flooded from Clinton to Obama. Before Obama won Iowa, Clinton held a 24 point lead among black Democrats. After he won, Obama gained a 28 point lead with the bloc.

“Although Obama won the black vote by margins as high as 9 to 1 in some states, this was not preordained. Clinton led Obama among African American voters in most polls until after he won Iowa,” former Obama adviser Dan Pfeiffer wrote in a Washington Post op-ed explaining why Sanders would have a hard time than his old boss.

That change helped Obama beat Clinton in South Carolina and then sustained him through the rest of the primaries and caucuses before he eventually assembled enough delegates to defeat her in a closely fought contest that played out in all 50 states.

Sanders, who will never be America’s first black president, can probably expect no such bounce. Back voters may give him another look, and some may move, but there’s no evidence to expect an en masse migration like Obama experienced.

Almost three out of four black Democrats support Clinton, according to an new NBC News/Survey Monkey poll. Just 12 percent support Sanders. He does better among Hispanics, but not by much, trailing Clinton 61-27 percent.

Sanders has been working hard to appeal to black voters, but has still struggled. Even in South Carolina, which black voters are likely to be a majority of those who vote in the state’s February primary, Sanders events are largely attended by whites. For instance, late last year, Sanders and Clinton visited two historically black universities in South Carolina that share the same campus. Clinton’s event was packed and all black, Sanders’ was about full and mostly white.

That doesn’t mean Sanders is incapable of reaching black voters, it will just be a much harder, slower process than it was for Obama. And it means a loss in Iowa to Sanders is far less devastating to Clinton in 2016 than it was 2008.