MIAMI — FOR nearly 20 years, Florida politicos watched Jeb Bush groom Marco Rubio for power. In the late 1990s, Mr. Bush, then a new governor, handed his young protégé Mr. Rubio, then a West Miami city commissioner, his political and financial network, asking friends like Al Cardenas — until recently the head of the American Conservative Union, which puts on the Conservative Political Action Conference — to give Mr. Rubio the connections and money he needed to ascend.

When Mr. Rubio muscled his way to the Florida House speakership after six years, former colleagues say, by double-crossing a friend and fellow Miamian, Gaston Cantens, Jeb Bush even gave him a ceremonial sword.

Now those same politicos are watching Mr. Bush try to dislodge the blade from his own back, as Mr. Rubio prepares to run against him in the Republican presidential primary. The announcement is expected in April.

The Bush dynasty may be “incredibly frustrated,” as one insider told me, that Mr. Rubio is interfering with what could be Jeb Bush’s last chance at occupying the office his father and elder brother held, but it shouldn’t be surprised.