The National Rifle Association called on its friends within the Republican party on Friday to defend its dogged opposition to greater gun controls in the wake of the Newtown shootings.

Current and former Republican leaders dominated the proceedings at the opening day of the NRA annual convention in Houston, Texas, with speakers defending the gun lobby's hardline resistance to new safety reforms. Sarah Palin, the former vice presidential candidate and governor of Alaska, led the charge, accusing President Obama of "exploiting tragedy" in his push for new regulations to prevent future Newtown disasters.

Palin lambasted Obama for "putting grieving parents on Airforce One" – a reference to the president's mobilisation of parents of some of the 20 young children who died at Sandy Hook elementary school in Newtown, Connecticut, to back his proposed gun control measures. "Obama has made them the constant backdrop of his campaigning."

She added: "Many Americans are desperate to respond to the tragedy, but emotion won't make anybody safer. Emotion is not leadership, it's the opposite of leadership."

The Newtown massacre, in which a lone shooter killed 20 five- and six-year olds and six of their carers, is the elephant in the room of the NRA convention, which has taken over a enormous convention centre in Houston city centre. All of the speakers alluded to the mass shooting in one form another, some defensively, others more brazenly.

Only one speaker had the courage openly to speak of "victory". Ted Cruz, the senator for Texas who led Republican opposition to new gun regulations in last month's US senate vote, told the rapt NRA crowd that "every vote that would have undermined the Second Amendment was voted down. That's your victory, it's the victory of the American people."

But Wayne LaPierre, the pugilistic chief executive of the NRA, took a contrasting stance, portraying the organisation that he leads, the nation's most powerful gun lobby, as under existential threat. He painted a paranoid vision of an America in which the NRA was having to fight for its survival against a liberal media and political elite bent on its destruction.

Without mentioning Newtown by name, he said the "media and political elites have been trying to blame the NRA for senseless violence" as a ruse to take away the constitutional rights of the American people. He said Obama and the New York mayor Michael Bloomberg, who is a leading voice for greater gun controls, were frequently on television "to scold or shame us, suggesting there's something wrong about law-abiding people who want to own firearms.

"The media and political elites can demonise us all they like but that won't stop us."

The lineup of the NRA's main day of policy debate underlined how politically partisan the gun debate in America has become. Five Democratic senators joined Republicans in voting down proposals for tightened gun laws that would have extended FBI monitoring of potential buyers for all gun sales, yet there were no Democrats on the podium on Friday.

Instead, there were six current or former Republican politicians, a former UN ambassador under George Bush and a Fox News contributor. Rick Santorum, who ran for the Republican presidential nomination last year, delivered a speech that seemed reminiscent of his 2012 campaign, or perhaps a dry-run for 2016.

He referred to Newtown as a "horrible tragedy" but said that the media had used "smoke and mirrors" to distort the truth of what happened. He then went into a prolonged reflection on European secularism and fondness for government.

Santorum likened Obama's politics to the godless French revolution and warned that in western Europe "churches are empty, nobody goes to church, it's a secular culture, a dying culture. They don't have rights other than the rights the government's decided to give them."