Business leaders won't necessarily make good politicians.

That point was driven home again and again on Tuesday night, during the fifth Republican presidential debate, which CNN broadcast from Las Vegas, where the topic of the conversation was leadership. Specifically, moderators wanted to know what kind of leaders the nine candidates would make in time of crisis, and the kinds of policies they would enact in the new era of terrorist attacks.

In that regard, the night belonged to the three Senators on stage, Texas Senator Ted Cruz, Florida Senator Marco Rubio, and Kentucky Senator Rand Paul, who circled each other like prize fighters, jabbing and swiping and also taking their licks like pros. By contrast, it was amateur hour for business magnate Donald Trump and former Hewlett Packard CEO Carly Fiorina, who opined about their ratings, or made vague remarks about the perils of having a "political class," respectively, but otherwise faded from view.

And the debate was a remarkable example of how leadership in politics and business are in the end very different animals. The former depends on cunning, building coalitions, and outreach. The latter is more frequently about the cult of the individual, and leading from the top down.

"I thought it was very unfair that virtually the entire early portion of the debate was Trump this, Trump that, in order to get ratings, I guess," Trump whined to co-moderator Hugh Hewitt. That was during a follow up to a question of former Florida Governor Jeb Bush about why he's more qualified to lead than the real estate billionaire, who garners as much as 41 percent of Republican voter support in some national polls, which is nearly triple the support for Cruz and four times that for Rubio.

Although the debates scarcely touched on the economy or business, the conversation was at times a vivid example for business owners, about how to lead people in their own companies. The upshot? The best way to lead is through a vibrant discussion of ideas.

The debates were also a reminder that business owners have something to learn from politicians. Forceful though some company builders may be, a strong personality does not necessarily equal a sophisticated understanding of how events play out on the world stage, or even within much smaller political structures at home, where elected officials must try to build coalitions to enact policy changes.

The most enlightening parts of the evening involved the senators' commentary about their votes in Congress on things such as the national telephone surveillance program, the readiness of the military, and immigration. Their responses provided some of the deepest insight into how these candidates would lead as commander-in-chief.

In particular, the sparring between Senators Cruz and Rubio, both of whom are now vying for the number two spot following Ben Carson's implosion in the polls, showed how political leaders need to use guile and their wits to win.

At one point, co-moderator Dana Bash questioned both about their different votes on the USA Freedom Act, signed by President Obama in June, which changes the way the federal government may collect data on the phone records of citizens. Cruz voted for the bill, while Rubio voted against it. The two opponents took it as an opportunity to drive home points about who has the strongest conservative credentials.

"We are now at a time when we need more tools, not less tools. And that tool we lost, the metadata program, was a valuable tool that we no longer have at our disposal," Rubio said.

Cruz responded by comparing Rubio to the community organizer Saul Alinsky. It was a subtle, if inaccurate, attempt to redefine Rubio as someone willing to align himself with left-of-center causes.

"What he knows is that the old program covered 20 percent to 30 percent of phone numbers to search for terrorists, Cruz said, by way of explaining his vote. "The new program covers nearly 100 percent."

Similarly, Paul used the same opportunity to bring up Rubio's wavering on immigration, and his support of the so-called Gang of Eight immigration overhaul bill in 2013, where he voted with Democrats, including New York Senator Chuck Schumer, in favor of the bill. The bill, which died in the House of Representatives the following year, would have provided undocumented immigrants with a path to legal citizenship, among other things.

"Marco is -- has more of an allegiance to Chuck Schumer and to the liberals than he does to conservative policy," Paul said.

Unlike Trump, however, Rubio did not talk about how unfair the debaters were for ganging up on him. Instead, he thanked Paul for handing him another 30 seconds to elaborate on his positions, and to critique Paul's own voting record.

These are the kinds of substantive exchanges that voters need to hear from their potential leaders before an election. While Trump and Fiorina have drive and charisma, without governing or political experience of any kind, they are unable to participate in the conversation. And last night was a reminder that leading a company is not the same thing as leading a nation.