Hillary Clinton. (Jonathan Ernst/Reuters)

Update 7:36 a.m. Thursday: Another warning sign for Clinton comes in the former of the highly respected Selzer & Company poll for the Des Moines Register and Bloomberg. It shows Clinton at 42 percent and Sanders at 40 percent. Clinton led by nine points in the last DMR/Bloomberg poll.

"Today" show host Savannah Guthrie asked Hillary Clinton a very simple question Wednesday morning: Are you getting worried about Bernie Sanders?

"No, I'm not nervous at all,'' Clinton responded. "I'm working hard, and I intend to keep working as hard as I can until the last vote or caucus-goer expresses an opinion. I'm excited about where we are."

That's the wrong answer.

Clinton should ABSOLUTELY be nervous about the state of the race with less than three weeks before voters in Iowa head to caucuses. There are warning signs almost everywhere she looks that suggest that the Vermont socialist is gaining momentum at exactly the worst moment for Clinton's chances at winning the nomination.

The new New York Times/CBS News national poll shows Clinton as a significantly diminished front-runner and Sanders as the surging insurgent. The 20-point lead she held a month ago has now been snipped down to single digits by Sanders.

In Iowa, the story is the same for Clinton. Suddenly her steady lead among likely caucus-goers has evaporated -- with a series of polls in the last few days suggesting that the race is a statistical dead heat.

Neither of those trend lines mean Clinton is going to lose the race -- in Iowa or nationally. But, they sure as hell can't make she and her team feel confident about their chances heading into the first votes in February.

In fact, Clinton's actions over the last week or so suggest that her insistence to Savannah that EVERYTHING IS GREAT isn't really how she views the race at the moment. Of late, Clinton has gone after Sanders very aggressively on his past votes on gun measures -- most notably a 2005 vote that granted full legal immunity to gun manufacturers if someone uses their weapon to commit a murder.  Clinton, in fact, ran an ad on the issue in Iowa and New Hampshire during President Obama's State of the Union speech Tuesday night.

Democratic presidential candidate Hillary Clinton released a campaign ad titled "I"m With Him" during President Obama's final State of the Union address on Jan.12. In the ad, Clinton expresses her support for Obama's executive actions on gun control. (HillaryClinton.Com)

When Clinton says in the ad that “it’s time to pick a side. ... Either we stand with the gun lobby or we join the president and stand up to them," you don't have to be a genius to know who she's talking about.

There are many Democrats who think that Clinton will be the nominee no matter what happens in Iowa and New Hampshire. That Sanders's inability to win over African American and Hispanic voters will doom him when the primary race moves to the south and west.

To which I say: Maybe.  There's little question that Clinton has dominated Sanders among non-white voters in the race to date. But, as recently as last month, she was dominating him in national polling and had a comfortable double-digit cushion in Iowa.  Neither of those things are true anymore.

Politics is a changeable business. History has shown that how one state votes influences how the states that follow it in the primary process vote. That's why losing Iowa and New Hampshire, which now seems possible if not likely, is a nightmare scenario for Clinton. And one that should make her very nervous.