WASHINGTON, DC(CNN) - Minnesota Sen. Amy Klobuchar, D- MN, will announce her plans for the 2020 presidential race on Sunday.
If she decides to run, she will join four other Senate Democrats who have either announced their bids or formed exploratory committees, and there are four more potential candidates in the Senate who are still on the sidelines.
That creates a new dynamic inside the Senate’s Democratic caucus.
The sheer size leaves even their Senate colleagues guessing.
“I’ve seen nine, I’ve seen seven. We’ll see what happens in the end.” Sen Bob Casey of Pennsylvania said.
Whatever the number, it creates a fascinating and potentially awkward dynamic among colleagues, one Democrats not running for president are keenly observing.
“I’ve been struck, frankly, at how well all of my different colleagues, who are running for president, have been able to handle the challenge of continuing to work together in the Senate,” Sen. Chris Coons of Delaware said.
When asked how long he thinks that will last, he answered, "I hope months, maybe even years. We'll see."
There are the friends, like Sens. Cory Booker of New Jersey, Kirstin Gillibrand of New York and Kamala Harris of California.
“They are friends, they are sisters. There will be some sibling rivalry. But at the end of the day we’re family.” Booker said.
There are some who are perhaps less so.
“I like all of my colleagues that are running. I like some more than others. I’ll leave it at that,” Sen. Sherrod Brown of Ohio said.
Nine Senate Democrats have their eyes on the White House - but what about the other 38?
“First, it’s important for a few of us to stay here in the United States Senate,” said Sen. Chris Murphy of Connecticut.
There’s also an array of policy and political fights the “left behind” caucus has their eyes on with the hope that their colleagues on the trail may actually amplify the effort.
Sen. Jeanne Shaheen of the crucial first in the nation primary state of New Hampshire won’t be endorsing anyone, but she will use the state’s outsized influence in the party’s primaries to influence the policy debate: “Having an opportunity to have so many people running for president who will go through this state who will hear the challenges we’re facing.”
Murphy said he wants a focus on a progressive foreign policy. Hawaii’s Sen. Brian Schatz prefers kitchen-table issues and climate change. Both want their colleagues to keep the competition friendly.
“Statistically speaking, if you’re running among seven or eight Senate colleagues a handful of governors and mayors and others, the chances of you returning to the Senate are very, very high. And so it behooves anybody who’s running to just be nice,” Schatz said.
And as to why so many from the world's greatest deliberative body fancy themselves executive material?
“It’s hard to be a Senator and not see yourself as president," Coons said. "I so far have resisted the temptation.”
There are several Democrats outside the Senate who’re also eyeing the White House.
They include former Housing and Urban Development Secretary Julian Castro and Rep. Tulsi Gabbard of Hawaii.