'Maybe this is the year we run the experiment?"

I knew immediately what David Axelrod meant. And it wasn't the first time I'd heard the sentiment expressed while in Las Vegas to cover last week's Republican debate. We were sharing notes after the debate, awaiting an appearance on CNN. Axelrod spoke of the philosophical divide within the GOP as to whether the party is best served by nominating a pure conservative or a more pragmatic centrist.

For many purists, history begins in 1980 with the nomination of Ronald Reagan. To them, his two decisive victories are evidence of the success that comes from putting forth someone who checks all the boxes. Bush 41, after being elected in Reagan's 1988 shadow, was too much the country-club Republican to ward off Bill Clinton's challenge in 1992. Only when a more conservative Bush (George W.) was nominated in 2000 did the GOP retake the White House. But it deviated from the winning script with John McCain and Mitt Romney and lost twice more.

Sounds pretty convincing. But there is an alternative history.

This one begins in 1964 with the nomination of Barry Goldwater, sufficiently conservative that Reagan delivered a legendary convention endorsement. But Goldwater was trounced by Lyndon Johnson, who carried 44 of 50 states and the District of Columbia. The GOP got back on track only by nominating the establishment's choice - Richard Nixon - in 1968, enabling back-to-back victories. This school of thought attributes Jerry Ford's establishment loss to post-Watergate angst, not ideology. And as for Reagan, he himself could not satisfy the Tea Party/Freedom Caucus forces that now control the party's nomination.

McCain and Romney didn't lose because they were insufficiently conservative, but because of the contortions required of them in primary and caucus season to appease evangelical Christians and other social conservatives whose influence has grown in the last three decades while independents have fled the party. The process demanded that Romney attempt to distinguish Romneycare from Obamacare despite the core similarities, right down to the individual (MIT economist Jonathan Gruber) who designed both. If Romney had run as the reasonable Republican who governed the bluest state in the nation, instead of a "severe conservative," he could have beaten Barack Obama. Instead, his flip-flops made him damaged goods.

Which brings us to 2016. When I asked Axelrod the outcome if a pure conservative like Ted Cruz is nominated, he said: "She [Hillary] would win by an even wider margin."

Former Pennsylvania Gov. Tom Ridge, who is supporting Jeb Bush, agrees. Ridge told me it would be "pure folly" to run an ideological conservative and warned against nominating a candidate who meets litmus tests advanced by "celebrity conservatives" who can be dominant on Fox News.

"Winning a presidential election is about addition not subtraction," Ridge said. "We need a candidate who will attract Democrats, independents, and millennials, and those with a severe edge are not most attractive to most Americans."

Another Bush supporter, Ana Navarro, thinks the "experiment" could benefit the party in the long term. "Let's see how nominating a noncompromising, ideologically pure, fire-breathing dragon works out," she told me. "Maybe we need to burn down to the embers as a party before we find some unity and start rebuilding from the ashes."

Charlie Gerow is a central Pennsylvania conservative who was once a field organizer for Reagan. In Las Vegas to support Carly Fiorina, he doesn't see the issue as conservatism vs. pragmatism.

"The issue in 2016 is 'insider' or 'outsider,' " he said. "Will the Republicans' best bet vs. Hillary be someone who's spent a career in politics, or somebody from outside the political class? A majority of GOP primary voters - and general election voters - are signaling that they're fed up with the business as usual of the political class. That's led to the rise of the outsiders."

He added, "I'm supporting Carly because she's a sensible outsider who can take on Hillary Clinton in ways no man in a gray suit and red tie can."

The day after the debate, Pat Buchanan argued in his syndicated column for the conservative route. Buchanan blamed Goldwater's 1964 blowout on the failure of establishment governors like Pennsylvania's Bill Scranton and Michigan's George Romney to support Goldwater after he defeated Nelson Rockefeller in California's primary. According to Buchanan, while Nixon "enlisted in Goldwater's campaign, Rockefeller, Romney, and Scranton, arrogantly refusing to accept defeat graciously, crippled any chance Goldwater might have had by demanding that the platform condemn the John Birch Society as equally extreme as the Communist Party and Ku Klux Klan."

Buchanan wrote that when the establishment "cut" Goldwater he was "dead" in the fall. "Thus did the GOP establishment earn the eternal enmity of the right," he wrote.

Which illustrates why no experiment in 2016 would finally settle the debate. Neither side would accept the outcome. Axelrod noted that if Cruz were nominated and lost badly to Clinton, conservatives would blame the media and say the moderates took a walk. And if Marco Rubio, Jeb Bush, John Kasich, or Chris Christie is nominated and loses, the retort will again be that they were insufficiently pure.

Politics, unlike the lab, gives us no placebo.

Michael Smerconish can be heard from 9 a.m. to noon on Sirius XM's POTUS Channel 124 and seen hosting "Smerconish" at 9 a.m. Saturdays on CNN.