As organizers hastily rewrote the script for a storm-shortened Republican National Convention in Tampa, a crowd of religious conservatives gathered a few blocks away to get a preview of what prominent and up-and-coming figures in their movement might say to delegates in coming days.

Republican presidential hopeful Mitt Romney’s campaign has sought to steer clear of topics such as abortion, birth control and same-sex marriage in favour of keeping the focus on President Barack Obama’s handling of the U.S. economy.

But speakers at Sunday’s Faith & Freedom coalition rally, hosted by the group’s evangelical conservative leader Ralph Reed inside a magnificently-restored 1920s-era Tampa Theatre, trumpeted the contentious issues as being at the core of the nation's survival and the “defining” choices facing Americans in this election.

Storm looming

Ted Cruz – a Texas Senate hopeful, the state’s former solicitor-general and current Tea Party favourite, who is also viewed as a rising star in the Republican party – even dared to tell a joke that invoked the looming storm’s biblical name.

“Be thankful for Isaac,” the Alberta-born Republican told the crowd. “If nothing else, it kept Joe Biden away.”

Cruz’s joke, which referred to the vice-president’s cancellation of a planned appearance in Tampa this week because of the looming storm, drew a laugh from the crowd in the theatre, which held several hundred people. The joke could prove controversial if Isaac were to strengthen and bring destruction on its northward path to the state’s panhandle — or potentially worse, veer toward New Orleans.

Much of the U.S. Gulf Coast was placed under hurricane warning as of Sunday evening, almost seven years to the day Hurricane Katrina made landfall struck the region and brought the most devastating natural disaster in U.S. history.

“You know, tidal waves often follow hurricanes, and a tidal wave is coming in November,” said Cruz, whose Cuban political refugee father and American mother worked in Alberta’s oil industry before moving to Houston when he was four.

The RNC is scheduled to convene amid worries about tropical storm Isaac, which threatens disruptions due to its proximity to the Florida peninsula. (Spencer Platt/Getty Images)

Obama’s support for same-sex marriage, Cruz added, meant that for the first time in history, a U.S. president had "declared himself an enemy of traditional marriage."

Republican 2008 presidential hopeful-turned-conservative radio host Mike Huckabee, who is now slated to speak at the truncated convention on Wednesday night, did not mention Romney in his brief remarks. Instead, he accused the Obama administration of leading an “assault” on people of faith through its move to require religious organizations to pay for their employees’ birth control.

Later, a small group of protesters who sat quietly in the theatre’s mostly empty balcony section for most of the two-hour event briefly interrupted Wisconsin governor Scott Walker at the start of his remarks, only to be drowned out by the crowd’s chants of “U.S.A.! U.S.A.!” Police escorted them from the venue without resistance.

Walker emerged as a hero to the conservative movement this summer after a bitter, unsuccessful recall attempt in his home state over his moves to curb state spending, which included eliminating union rights for most public workers.

President has 'turned his back on faith'

Hank McKeithan, a defence department worker and Tampa area tea party member who attended Sunday’s faith rally, told CBC News he liked the “optimistic” message that Cruz and other speakers delivered.

McKeithan said he believes Obama “has basically turned his back on faith” with his pro-choice and pro-gay-marriage positions. He also criticized the president for giving preference to “Muslim extremists” over Israel in the Middle East.

Romney has mostly waded into the religious freedom debate only to offer vague denunciations of the “secular agenda” of his Democratic rival Obama, who has written openly of his Christian beliefs for years.

So far in the campaign, Romney has opted not to put his Mormon faith at the centre of his pitch to American voters, opting instead to emphasize his experience as a successful business leader and convince them he is better suited than Obama to handle the country’s economic recovery.

But that could change at the convention this week, as Romney attempts to re-introduce himself to the American public on the largest stage yet.

The Republican candidate has also faced questions over whether being a Mormon could turn off religious conservatives, with some evangelicals openly labelling Romney's church as non-Christian.

Audience member McKeithan said he saw Romney in the same light as the late conservative icon and former president, Ronald Reagan, who “lived his faith.”

Romney, he said, “doesn’t need to expand that he’s a Mormon and he’s at temple every Sunday or whatever.”

”Let his actions speak for him,” he said.

Newt Gingrich, once Romney’s bitter rival during the Republican primaries, also came to Romney’s defence at Sunday’s event, telling the crowd that he was delighted that Romney “has a faith.”

“And I'm delighted that it matters to him," said Gingrich. "That's a big improvement amongst our left-wing secular elites."

Leading into the convention, the Romney campaign has struggled to fend off a firestorm of controversy sparked by Republican Senate hopeful Todd Akin, who suggested earlier this month that women’s bodies can prevent pregnancy if they are victims of “legitimate rape.”

Akin has since apologized but refused to withdraw his candidacy, despite the urging of Romney and other prominent Republican figures.