Marco Rubio sent praising note to Jeb Bush ahead of his announcement

As former Florida Gov. Jeb Bush formally launches his White House bid Monday in Miami, his one-time mentee, Marco Rubio, now a Republican primary threat, issued a statement of good will on Bush's entry into the race—a rarity in presidential campaign politics.

"In politics, people throw around the word 'friend' so much it often has little real meaning. This is not one of those times. When I call Jeb Bush my friend, I mean he is someone I like, care for and respect" Rubio said.

"He and I have worked closely together for many years, on issues big and small. He is a passionate advocate for what he believes, and I welcome him to the race, "Rubio added.

By Rubio's own admission, Bush was a significant influence on the U.S. senator, ever since he first became a rising GOP star after being elevated to speaker of the Florida House, and Bush was finishing his 2nd term as a popular governor of the Sunshine state.

Bush even gave him a sabre as gift when he became speaker in 2005.

''I'm going to bestow to you the sword of a great conservative warrior," Bush told Rubio then, according to a local report. Rubio took the sword, dubbed the "Sword of Chang" by Bush, and waved it like a torch.

In his 2012 book, “American Son,” Rubio described his admiration for Bush.

"I was most influenced by the creativity and daring of Governor Jeb Bush," Rubio wrote. "A one-man idea factory."

Rubio described him as "the man he admired most in Florida politics."

In April, Rubio launched his presidential campaign in The Magic City, across a placid Biscayne Bay.

"Before us now is the opportunity to author the greatest chapter yet in the amazing story of America. We can’t do that by going back to the leaders and ideas of the past," Rubio said to the cheering crowd of thousands, many Latino, at the iconic Freedom Tower in downtown Miami. His words, an implied jab at not only the Democratic frontrunner Hillary Clinton, also seemed at directed at Bush.

Bush allies have indicated privately to Fox News that the Bush campaign will have to go after Rubio, in an effort to deflate some of the growth Rubio has gained in the last few weeks as the Cuban-American solidifies himself with Bush, Walker and a couple of other rivals near the top of most recent GOP polls.

And the competition for supporters and donors is on, especially in Florida, where the March 15th primary will be a significant battle ground for each campaign. The Bush campaign released a statement last week that they had picked up three key supporters from Rubio's home turf.

Three Republican, Cuban-American  members of Congress in South Florida, including U.S. Representative Ileana Ros-Lehtinen, a close ally of Rubio (Rubio had even interned for her at one point) – have all endorsed Bush.

But on Monday morning, after the Bush campaign released a well-produced video with a theme of optimism and positivity, the good will was returned on Twitter by Rubio's former mentor.

"Thanks Marco," Jeb Bush tweeted. "Glad I can do it in our hometown. See you out there!”