“I tell you all these things not to get you nervous, but to get you depressed,” Sen. Bernie Sanders, speaking about climate change, said at a town hall meeting in Grundy Center, Iowa, over the weekend.

Hours later in Des Moines, it was Joe Biden describing the state of Trump’s presidency more broadly as “extremely, extremely worrisome.” Sen. Elizabeth Warren admonished supporters in Davenport that “this is a time of crisis in this country.”

Democrats have fretted for more than a year about how to choose a nominee. And for those who loathe Trump, the imperative to remove him from office has remained high since the minute he won election in 2016.

But many Democrats did not suspect a year ago that the final stage of the campaign would begin with open conversations about the prospect of a World War III. Or an impeached president.

Standing in the photo line at a raucous Warren event Sunday, a high school senior said he worried about his friends being deployed to the Middle East. The Iowa Starting Line news site reported that during a single day campaigning with Sen. Amy Klobuchar recently, attendees at three separate events had “compared Trump to Adolf Hitler’s rise in Germany.”

At a Biden event at the minor league baseball stadium in Davenport, a man asked, “Can America survive Trump in office for another year?”

A collection of answers rang out from around the room: “No.” And before Biden addressed the crowd, Scott County Supervisor Ken Croken cast the weight of the upcoming caucuses in equally somber terms.

“It’s my experience that people act for one of two reasons,” he said. “One, something good will happen if they do, or two, something terrible will happen if they don’t. This year, in the 2020 election, we actually have both.”

He said, “I fear that our democracy will not survive four more years of the imperial Trump presidency with his lack of understanding and respect for the Constitution.” He said he feared the planet might not survive, either.

The turn of the calendar — and the abrupt reminder of what Croken called Iowa’s “truly awesome responsibility” of caucusing — has done little to improve the state’s mood. In fact, impeachment and the developments in Iran appear to have exacerbated voters’ anxiety about their indecisiveness on an alternative to Trump.

Sanders, Biden and Pete Buttigieg are locked in a three-way tie in Iowa, each with 23 percent support, followed by Warren at 16 percent, according to the most recent CBS News poll.

In addition, Iowans still aren’t sure — after more than a year watching candidates here — that any of them can beat Trump. Asked to describe the candidates’ chances of defeating the Republican president, pluralities of Democrats said Sanders, Biden, Warren and Buttigieg can “maybe” win the general election, according to the poll. Fewer than 40 percent of Democrats say any of those candidates “probably would win.”

“I think [Trump] has an excellent chance of being reelected, no matter what,” said Tracy Freese, the Democratic Party chairwoman in Grundy County, where she introduced Sanders at a town hall over the weekend. “There are plenty of Democrats who are realistic.”

The darkening mood has not changed enthusiasm for the election itself — even if it is tinged with anguish. Crowds in recent days were still jamming into coffee shops, community centers and high school gymnasiums to cheer their candidates.

Yet even energetic caucusgoers can have frayed nerves. Some Democrats worry an escalating conflict with Iran could help Trump politically. And despite projections for a record caucus turnout, some party officials remain unsure what to expect.

“Are we too wide of a field still that people are turned off by that?” Freese asked. “Or are we so fired up because of things like impeachment and Iran, now … are we so fired up that we will turn out even harder to caucus? I have no idea.”

At least some of the electorate’s shifting mood can be attributed to the calendar. Iowans become more serious about the caucuses as they draw closer every election cycle, said Roxanne Conlin, a former U.S. attorney and former candidate for governor and Senate in Iowa. And the “mortal danger” posed by Trump, she said, has long been on Democrats’ minds.

Still, said Conlin, a Klobuchar supporter, “The Iran decision, if you can call it that — oh, my God.”

Biden frequently warns audiences that eight years of Trump will “fundamentally change the character of the nation.” In the audience at one of his recent events, the man who asked if the United States could survive a second term of Trump’s presidency suggested that recognizing the urgency of replacing him isn’t the problem — and never has been.

“People sense that urgency, but they don’t know the solution,” said Bruce Peterson, a canoe builder.

He said he didn’t know the solution, either. But more than ever before during Trump’s presidency, he said, “These last two months make me apprehensive.”