It looked like Julián Castro and sounded a lot like him, but confirmation that he plans to run for president in 2020 came from his identical twin, Joaquín Castro.

In a moment that made comically visible the doublespeak exercised by virtually every modern presidential candidate in the run-up to their official announcement, one twin brother said Thursday the words that the other squirmed to avoid saying for legal and political reasons.

Joaquín Castro, a Democratic congressman from Texas, seeing his one minute-older brother being pressed by Stephen Colbert in a joint appearance on CBS's "The Late Show With Stephen Colbert," jumped in to make it as official as any brother can.

Colbert was grilling Julian, who announced this week that he is exploring a presidential run and will make a final decision in January, on why the former Housing secretary couldn't just state the obvious.

"Why do you have to wait that long? What are you going to find out now between now and Jan. 12? Why can't you just tell us?" Colbert asked.

"I'll speak on his behalf, here," Joaquín interjected, getting a smile and nod from Julián. "He's going to run for president. ... For the FEC lawyers: He didn't say it! I said it."

Once someone says the magic words, "I'm running for president," the person almost instantly becomes a candidate in the eyes of the Federal Election Commission, which means they then have to file paperwork with the agency and start accounting for every dollar raised and spent, all of which has to be publicly disclosed.

So, until they're ready to announce, potential candidates in both parties avoid uttering those words like Hogwarts students avoid saying Voldemort's name.

Most candidates, though, don't have identical twin brothers to say those magic words for them.

For campaign finance watchdogs, it's just the latest example of the "charade" of the "purported noncandidacy," as Paul S. Ryan of Common Cause has put it, where people whom we all know are running for president avoid admitting it to set their own timeline for an announcement, regardless of what the rules say.