So here's how experts are advising the candidates to use their Senate platform:
DO STUFF THAT GOES VIRAL
The Senate Judiciary Committee is a popular place to attract attention. It not only debates the day's hottest issues, including immigration and voting rights, but also considers nominees for the Supreme Court, attorney general and federal judgeships.
Harris, Booker and Klobuchar are members, and they've taken full advantage.
Harris used the platform to help her leap to national stardom during last year's hearings on the nomination of Brett Kavanaugh, who would become a Supreme Court justice.
She grilled him on whether he had been talking with a law firm with ties to President Donald Trump about Special Counsel Robert Mueller's investigation of possible collusion between Russia and the 2016 Trump campaign.
"I'm not remembering," Kavanaugh said. Harris was irate. Kavanaugh pressed her to name a person she had in mind. Harris would not relent.
"I think you are thinking of someone, and you don't want to tell us," she said.
BE ONE OF THE PEOPLE
Empathy matters. Booker frequently cites his urban roots, and his Judiciary perch offers a public way to make the point.