Conservative internet publisher and activist Andrew Breitbart, who inspired the Right and infuriated the Left, collapsed and died early Thursday, at age 43. Breitbart, who reportedly had heart problems, started out as a behind-the-scenes deputy to web pioneer Matt Drudge. After leaving The Drudge Report in 2005, he rapidly built an internet publishing empire that began with, and now includes such sites as Big Journalism, Big Hollywood, Big Government, and others. In the process, Breitbart became a brash defender of conservative causes, and the muckraking nemesis of liberal politicians and groups. His posts, including photos and videos, have been credited with — or blamed for, depending on your point of view — taking down foes from ACORN to former House Democrat Anthony Weiner. Here, a sampling of views, from those on both the Left and Right, on what Breitbart's loss means:

The conservative movement has lost a driving force
Breitbart was a "powerful force," GOP presidential candidate Rick Santorum tells Politico. "What a huge loss, in my opinion for our country, and certainly for the conservative movement. I'm crestfallen."

Breitbart was molding tomorrow's conservatives
Andrew Breitbart was "a warrior," says Michelle Malkin at her blog. "He was kinetic, brash, relentless, full of fight, the bane of the Left, and a mentor to the next generation of right-wing activists and citizen journalists.... He will be greatly missed, but his legacy online and in the conservative movement is built to last."

His passion set him apart
"[Our site] has a long history with Andrew Breitbart," says Media Matters' Ari Rabin-Havt, noting that the liberal watchdog website grappled publicly and frequently with Breitbart. "We've disagreed more than we've found common ground, but there was never any question of Andrew's passion for and commitment to what he believed."

He took risks when others didn't dare
"In some ways, Andrew was our Merry Prankster," says Ed Morrissey at Hot Air. "He was willing to take risks and look foolish in order to make a point or win an argument, with more courage than most would muster." Who can forget how he grabbed the mic at former congressman Anthony Weiner's press conference, "demanding vindication" from all who disparaged him for posting the tawdry photos that brought down the disgraced Democrat?

The Right has lost its ace bomb-thrower
Breitbart, "a hard-partying Hollywood media gadfly," was the unlikely and "self-appointed spokesman of the Tea Parties, defending the movement from all charges of racial resentment-based motivation," says Alex Pareene at Salon, "making always entertaining if frequently... baffling television appearances, saying outrageous and often indefensibly inflammatory things for attention, and tweeting constantly." He had "generally a toxic influence on the national debate," probably because, for him, it wasn't about tax rates or foreign policy. "It was about fighting and bomb-throwing and arguing and winning a war against an enemy he built up in his Hollywood-inspired imagination to be massive and powerful."

He was a tireless, irreplaceable champion
"Like everyone, I'm in a state of shock, stunned," conservative talk-radio giant Rush Limbaugh tells Radio Equalizer. "Andrew Breitbart was indefatigable in every endeavor of his life. His passing is such a huge loss, to everyone who knew him. There was, literally, no one like him. As such, he is a legend now. He was culturally refined and a bulldog at the same time. And he was credible, always credible. It's just a shame."