How 2020 Democrats reacted to Beto

Why it matters: It's too early to tell who's going to be the nominee, but Beto's early buzz is clearly something his Democratic opponents aren't taking lightly and can't afford to ignore.

• Fundraising is particularly important for 2020 candidates because they can't qualify for the DNC debates unless they have donations from at least 65,000 people. As Booker wrote in his email: "The reality is every new person in the race makes the potential debate stage more crowded."
• O'Rourke raised a record $80 million for his 2018 Senate campaign in Texas, and $20 million of that came from out of the state.

Other candidates welcomed Beto to the race with a simple tweet, like John Delaney.

• Julián Castro's team emailed supporters on the morning of O'Rourke's announcement with the news that he'd received over 30 endorsements from appointed and elected officials in Texas.
• Sen. Amy Klobuchar was asked about O'Rourke's campaign during a CNN interview, to which she said: "I think competition is good for our party."
• Sen. Kirsten Gillibrand seemed unfazed by O'Rourke's announcement — she met with Stacey Abrams yesterday.

Go deeper: Everything you need to know about Beto O'Rourke.