Rubio isn’t automatically inheriting Bush’s supporters and donors in Florida as he and his allies assumed he would:

Now with Bush out of the race, many Rubio supporters and campaign observers expected that the governor’s donors and active supporters would quickly switch allegiance to the senator. But that hasn’t happened.

“There’s a lot of people that are going to wait for Gov. Bush before they do anything, both monetarily and with their personal support,” said Will Weatherford, a former Florida House speaker who supported Bush before endorsing Rubio.

Bush reportedly has no plans to back Rubio, so the senator will probably be waiting for a very long time before many of Bush’s allies lend him aid. It is well-known that Bush and his allies resented Rubio’s presence in the race, and it frankly never made much sense that Bush supporters would suddenly switch over to the campaign that did so much to ruin the former governor’s presidential bid. This report confirms that Rubio can’t count on Bush supporters coming over to his side.

Rubio’s other problem is that many Bush donors don’t see the point in throwing more money away on a vain anti-Trump cause:

In most cases, they doubt Rubio will prevail and don’t want to spend more time and money fighting an opponent they’ve already failed to stop.

“If you don’t see a donor rush, it’s because people are seeing what I’m seeing: Show me how Trump can be beaten,” said Al Cardenas, a Miami-based lobbyist and conservative activist who is a longtime Bush friend and former Rubio employer.

Rubio’s inability to win has naturally discouraged people sitting on the sidelines from throwing their support behind him, and the fact that he still hasn’t won a primary gives donors good reason to doubt that he can win in Florida. That lack of financial backing will make it very difficult to compete in Florida, and the campaign is already running low on cash:

One serious problem for Rubio is money: His campaign had only about $5.1 million as of Feb. 1 — not nearly enough to run an effective statewide ad campaign across the state’s 10 media markets.

Many of Bush’s donors could help fix this, but as long as Bush holds a grudge against Rubio that seems unlikely to happen. It is fitting that Rubio won’t have this support when he absolutely needs it at least in part because of his perceived betrayal of Bush.