7 Things We Learned From the 3rd GOP Debate

The third Republican debate may have been the most consequential so far.

With almost half of the candidates on stage at the tipping point between being a top contender or fading back into the pack, the stakes were high. One-time favorite Jeb Bush was in need of a spark. And Marco Rubio was quickly becoming an establishment alternative to Bush. Not to mention -- Ben Carson is on the cusp of overtaking Donald Trump for the front of the GOP pack.

Still, all the buzz was about the second-tier race: Bush and Rubio dominated post-debate coverage, making it hard to remember that Trump and Carson garner almost triple their support in almost every recent national poll.

Here are the seven main takeaways from Wednesday night's third presidential debate:

1.Marco Rubio isn't flying under the radar anymore. He came out of Wednesday's night debate with rave reviews. There's no doubt he had a strong performance and his showdown with his former mentor, Jeb Bush, struck a brutal blow to the one-time frontrunner's already shaky candidacy. Today, the Rubio campaign may be flying high and even raking in some post-debate donations, but there is a downside to being on top. Now there's no way Rubio can fly under the radar anymore. With polls showing Rubio rising and last night's performance behind him, he will face more scrutiny and be a target of rivals. A campaign on the rise often brings new difficulties, but that's only something eventual winners have to go through.

2.Jeb Bush is in serious trouble. There's no way to sugarcoat last night for Bush's campaign, not to mention his supporters. He not only didn't have a break out moment, but his face off with his one-time protg Marco Rubio was a stand-out moment for his rival. The Bush camp telegraphed they were going after Rubio's voting record, making absolutely sure everyone, including the Rubio camp, were ready when that hit came. The problem: Bush had no comeback. Of course, one bad debate doesn't kill a candidacy, but the former Florida governor has been struggling in the polls and now it's time to keep donors from going into full-on panic mode. There's another debate around the corner-Nov. 10 - and everything could be riding on that trip to the podium.

3.No harm, no foul for Ben Carson and Donald Trump. The two frontrunners in this race are Trump and Carson -- at least that's what the polling said. But they definitely weren't the main attractions last night. Trump even went 28 minutes at one point without speaking. They didn't flop, but no one is raving --or even talking about --their largely-absent performances. They made no errors, but there were no break out performances either. It's status quo for the two contenders at the top of the polls. Will it matter to voters? We will be watching the next slate of polls very closely.

4.It's hard to go after Ben Carson. The neurosurgeon is on the cusp of becoming the national frontrunner for the GOP nomination. And his favorability numbers are through the roof -- often topping 85 percent nationally and in Iowa. So it's no surprise that most candidates seemed wary of going after him. Attacks from John Kasich, jabbing at Carson's tax and Medicare plans, didn't seem to damage him. "Folks, we got to wake up. We cannot elect somebody that doesn't know how to do the job," he said. And to a question from the moderators about Carson's involvement on the Costco's board, the audience gave the moderators a chorus of boos. Indeed, polls show that voters opt for Carson because of his honesty and empathy -- and trust other candidates more on policy.

5.Marco Rubio is angling himself as outsider. Rubio may be a member of Congress, but in the year of the outsider, don't tell him that. While the Republican-led House is constantly in the headlines for its dysfunction, the first-term Senator is distancing himself from the unpopular institution - and the unpopular Republican establishment. "That is exactly what the Republican establishment says, too, wait in line," he said last night, when asked whether he should accomplish more in the Senate before running for President. "Wait for what? This country is running out of time." Carson and Trump have had massive success so far in the GOP nomination race despite having never been elected to office.

6.The news media is a popular target for Republicans. Not since Newt Gingrich's famous outburst in 2012 have we seen such aggression by a group of candidates against the political news media. Ted Cruz had a strong debate, largely thanks to a strong attack against the moderators. "The questions asked so far in this debate illustrate why the American people don't trust the media. This is not a cage match," he said. "How about talking about the substantive issues?" he asked as the crowd erupted in applause. Cruz's strong poll numbers, focused campaign and large Super PAC bank are likely to make Cruz one of the last candidates standing. But Rubio also hit the media - a popular target for Republicans. "The Democrats have the ultimate super PAC," he said. "It's called mainstream media."

7.Moderating a presidential debate is hard. Republican candidates weren't happy about how the Republican debate went last night -- and they weren't afraid to say it. RNC Chairman Reince Preibus said that CNBC "should be ashamed" about the way they ran the debate. But CNBC spokesperson Brian Steel shot back, saying: "People who want to be President of the United States should be able to answer tough questions." The candidates also weren't afraid to criticize the moderators on stage. "Are we really talking about getting government involved in fantasy football?" Christie asked. "Can we stop?" With a full stage of 10 Republicans, all trying to angle for more speaking time, it's hard to keep things under control.