Marco Rubio aggressively tried to push Florida to the political right during his two-year stint as speaker of the state's House, often warring with the more moderate Republicans who ran the Florida Senate and then-Gov. Charlie Crist, a centrist Republican.
From the start of his speakership in November 2006, Rubio pushed a controversial idea to eliminate all property taxes in the state, making up some of that revenue with a 2.5 percent increase in the Florida sales tax. Crist did not support the idea, and it did not become law.
When Crist sought to expand casino gambling in the state, Rubio, joined by other conservatives in the state's House, filed a lawsuit to block the move, arguing the governor had overstepped his authority by not getting the legislature's approval. The Florida Supreme Court sided with Rubio.
After Crist, by executive order, created new emissions standards for Florida cars and utilities as part of an initiative to combat climate change, Rubio blasted him for imposing "European-style big government mandates." Rubio and the legislature later passed a bill that weakened the impact of Crist's climate change provisions.
"I think Marco is a severe conservative, really far to the right, but probably the most talented spokesman the severe right could ever hope for," said Dan Gelber, who was leader of the Florida House Democrats during Rubio's tenure as speaker. "He has a televangelical ability to communicate. I thought his policies didn't match his rhetoric."
Rubio's leadership in the Florida House makes him unique among the 2016 GOP candidates and distinct from President Barack Obama.
Like Obama, Rubio served in his state's legislature for about eight years, was elected to the U.S. Senate and then opted to run for president without serving a single full term.
But in interviews, Rubio, wary of being likened to the president, has started noting a key difference between his experience and the president's. Obama, says Rubio, was a "backbencher" in the Illinois State Senate, not the House speaker.
Rubio rose to power in Florida in part because of an advantage Obama did not have in Illinois: term limits. House members in Florida are allowed to serve only four consecutive terms, for a maximum of eight years in office. And the speakership of the Florida House, by tradition, ends after two years.
So Rubio, elected to the state House in 2000, quickly became the House majority leader. in 2003, he successfully secured the votes, against a number of GOP rivals, to be designated the House speaker.
But in Florida's unusual system, the speaker is often tapped far before he enters the office. Rubio's tenure as speaker would not start until November 2006.
In the years before he was to assume the speakership, Rubio, as past speaker-designates had done, traveled the state, raising money and campaigning for other Republicans. But he also did something unique: soliciting policy ideas that Rubio could build into a governing agenda to enact as speaker.
It was modeled, Rubio has said, on the 1994 Contract with America that U.S. House Republicans created and then attempted to implement once in power.
The ideas were put into a book Rubio wrote called "100 Innovative Ideas for Florida's Future."
Some of the 100 provisions were vague and non-controversial, such as creating a website that offered details of the state's budget. Others were surprisingly liberal for the conservative Rubio, such as requiring that 75 percent of Florida government vehicles run on alternative fuels and creating tax credits for TV and movie companies that filmed in Florida.
Others expressed strong conservatism, including the property tax provision and a requirement that any tax increase must pass with a super-majority in the legislature.
In 2006, as Rubio was preparing to start his speakership, Jeb Bush was finishing his tenure as Florida's governor. Rubio, like other young Florida GOP lawmakers, deeply admired Bush and said he wanted to follow the model of the outgoing governor, who was known for his interest in the details of policy.
Bush famously presented Rubio a golden sword in a ceremony on the floor of the Florida House at a celebration of Rubio's ascension to the speakership, in a kind of passing of the conservative torch in Florida. Rubio opted to hire a number of Bush's outgoing aides to work in the state House.
If Bush was an ally, Crist quickly became a rival. Crist won the governor's race in 2006 while many Republicans across the country had lost. He was expecting to shape politics in Florida, with the Republicans in the House and Senate following his lead.
Instead, Rubio, then one of the youngest speakers in Florida history at age 35, dueled with the 50-year-old Crist over control of the agenda in Tallahassee. Crist attempted to govern as a moderate, while Rubio pushed the conservatism that had defined Bush's time as governor.
"It was Charlie Crist and the moderate Senate versus the conservative House," said Adam Hasner, who served as the Florida House Majority Leader under Rubio and remains a close ally. "While we passed more than half our agenda, many of the big ideas and the conservative policy items were blocked by Crist and the Senate."
Crist, a very genteel politician, rarely directly acknowledged tensions with Rubio and the Florida House. Rubio, on the other hand, at times publicly scolded the governor from his own party.
On property taxes, Crist won. Rubio emphasized that he was proposing was the "single largest tax cut in Florida history" by getting rid of property taxes completely. Crist simply wanted to reduce them.
But Rubio's idea to hike sales taxes drew opposition from Democrats and even some Republicans, who worried it would both unfairly hit the poor and would allow some in the GOP to be cast as raising taxes.
"The press hailed it as a big win for Charlie Crist, and a big loss for me and the House," Rubio wrote in his 2012 memoir "An American Son," describing the property tax dispute.
He added, "I suppose it was, but it was bigger loss for the people of Florida. A speaker's legacy is achieved in his first year, and his influence wanes in the second year. For better or worse, property tax reform would be my legacy, and it was incomplete, to put it charitably."
After that first defeat, Rubio pushed for a more modest measure, a cap on property taxes, as well as an overall limit on state government spending. Neither of these ideas was approved, with Crist unwilling to strongly support them.
Crist succeeded even when it came to one of Rubio's 100 ideas. Crist had signed into a law a Rubio-backed provision to make Florida's presidential primary earlier, so the candidates would spend more time in the state.
This increased the clout of Florida, but the result was another defeat for Rubio. The House speaker endorsed former Arkansas governor Mike Huckabee, one of the conservative candidates in that race. In the final week before the January 2008 primary, Crist announced his support for the moderate John McCain, who won. The governor looked like a kingmaker, while Huckabee finished in fourth.
Rubio won on other issues, such as casino gambling. And many of his original 100 ideas, particularly on small-bore issues, were enacted. Rubio aides have said 57 of the proposals were enacted, although the well-respected website PolitiFact has concluded only 34 of them did.
But after two years, Crist had often outmaneuvered Rubio, and his approval ratings made him one of the more popular governors in the country.
Rubio, as his speaker tenure was ending in 2008, admitted frustration. He would be leaving the legislature because of the term limits and did not have future political plans. Crist, it seemed, would continue to lead Florida as governor or perhaps take an even bigger step, as his name was being floated as a potential vice-presidential candidate with McCain.
In April of that year, according to the Tampa Bay Times, Rubio sent a series of off-the-record e-mails to Florida political reporters. The paper was not allowed to publish the messages, but Rubio then was interviewed and acknowledged some disappointments.
"Rubio lashes out as a stressful term winds down," read the headline from the Times.
Crist's victory in their rivalry turned out to be temporary. When a Florida U.S Senate seat opened up in 2009, Crist opted to run for it. Rubio challenged him, fully aware that Crist's record of more liberal stances as governor would be difficult to defend in a Republican primary.
Rubio won a race that drew national attention and was elected to the Senate in 2010. It is now Rubio who could be elected president or vice-president in 2016, while Crist is out of politics, having lost an attempt to become governor again in 2014.
"I didn't realize it at the time of course, but the seeds for my election to the U.S. Senate in 2010 were planted in the spring of 2007," Rubio later wrote.