Call it the nice primary.

As the contest for the 2020 Democratic nomination heats up, the five senators in the race have taken turns dousing each other with praise while saving the zingers for President Donald Trump.

Sen. Kirsten Gillibrand, D-N.Y., said she thinks it's "amazing" that Sen. Kamala Harris, D-Calif., is running against her — news Sen. Elizabeth Warren, D-Mass., called "terrific."

"There will be some sibling rivalry. But at the end of the day we're family,” Sen. Cory Booker, D-N.J., said in an interview on "The View."

"Great people," Sen. Amy Klobuchar, D-Minn., the most recent entrant into the already crowded primary field, told MSNBC Monday of her newly minted rivals.

So far, the congenial nature of the field stands in stark contrast to the viciousness of the 2016 Republican primary, which featured derisive nicknames, an insinuation about the size of the now-president's genitalia, a meme mocking Texas Republican Sen. Ted Cruz's wife, entire debate performances tailored to taking down another candidate and more. But that will change soon, political strategists predicted.

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"The plane has just crashed in the Andes. For right now, everyone's cooperating, but soon they are going to start thinking about who can be eaten first," Rick Wilson, a Republican strategist who opposes President Donald Trump, said. "Politics is always cooperative right up until it’s absolutely not cooperative in any way and everyone seeks to destroy everyone else."

Strategists told NBC News that with nearly a year to go until Iowa's first in the nation caucus, it's smart for Democrats to play nice for now. Voters are exhausted and still recovering from the longest government shutdown in U.S. history, they said, and with Trump tweeting attacks from the White House, Democrats will look stronger by holding their fire on each other.

“We just got done with one election where we did well. The smart folks don’t want to screw things up, we’ve got an enemy in Donald Trump, we’ve gotta stay focused on that,” Democratic strategist Jim Manley said.

Republican strategist and MSNBC analyst Susan Del Percio agreed.

"I don’t think that the primary voters want to see a blood bath right now," she said. “There’s so much energy to defeat the sitting president, they have to be careful that they’re not willing to kill each other and be weaker as a result.”

"I can't stress this enough — it is so early," Del Percio added. "The Republican primary didn't get god-awful until Donald Trump entered."

Trump launched his campaign for president in June 2015, after a number of GOP politicians, including a handful of senators, had announced their bids.

Strategists said the punches amid 2020 Democrats would start to fly soon — in part because candidates will need to start differentiating themselves amid a crowded field and in part because voters want to be sure to choose someone who can take on Trump.

"One of the things voters are going to be looking at is somebody who is going to be a fighter, someone who is going to throw down with Trump. They’re going to look at somebody who is nimble on their feet, who can not only take a punch but land a punch," Manley said.

Del Percio said she expects the gloves to come off in August, when the Senate recesses for five weeks and those candidates won't all be at work together every day.

Wilson expects blows to come before the first Democratic debate in June.

"The minute one of these candidate emerges and Democratic primary voters say he or she — that’s the one who can really knock Trump down. That’s the minute the clock starts running for everybody else," he said.

In Wilson's opinion, it's Booker — whose vegan diet Gillibrand revealed she knew all about in a lighthearted video filmed for Marie Claire before the longtime friends officially announced their competing bids — who gets eaten first in his Andes Mountains scenario.

“You don’t lead a campaign in the era of Donald Trump talking about we want love," WIlson said. "That’s not what the Democratic base wants right now. They want rivers of blood.”