Cisneros is just one of several prominent Hispanic leaders who are promoting Castro. Democratic National Committee Finance Chairman Henry Muñoz told BuzzFeed in May that Castro “deserves to be on the short list,” and New York City Council Speaker Melissa Mark-Viverito, who was born in Puerto Rico, said the concerted effort from Hispanic leaders to promote Castro reminded her of the united rally around Sonia Sotomayor when she was under consideration for a Supreme Court nod.

Clinton and Castro haven’t spoken since they appeared together on a panel in Washington in April, but people close to the campaign acknowledged that it’s politically useful for the candidate to keep his name in the public conversation, long before her operation formally starts vetting prospects. That way she can implicitly emphasize to Hispanic voters that she is taking their concerns about representation seriously.

“A lot of Latino Democrats are concerned about what happens if Marco Rubio becomes the [Republican nominee], or Jeb Bush, or even if Scott Walker becomes the nominee and he chooses Rubio to be the VP,” said a Democratic strategist close to the Clinton camp, adding that many see Castro as an easy solution to the dilemma.