Clashing with Pope Francis couldn't stop him.

Ridiculing George W. Bush's response to 9/11 in a state that has long adored the Bush family didn't slow him down, either.

After his resounding victory in South Carolina on Saturday, Billionaire mogul/presidential candidate Donald Trump is still standing tall, and it's time for the GOP Establishment to start taking his campaign very seriously.

For Trump Haters, It's Time to Panic

Even Trump gets this. In his victory speech tonight, he addressed GOP voters directly who feel that as the candidate pool narrows — which it already has, with the concession of former Florida Governor Jeb Bush — establishment voters will coalesce around Marco Rubio. He told a cheering audience:

"They don't understand that as people drop out, I'm gonna get a lot of those votes also."

To understand why Trump's victory is so important, we need to understand what makes South Carolina unique among the early battleground states.

Is South Carolina the GOP's canary in the coal mine?

South Carolina has been called the gateway to the Bible Belt and is also known as the "First in the South" primary. Historically, South Carolina's primary winner has gone on to be the national GOP nominee in every recent election since 1980, except for 2012 when Newt Gingrich won the state's nomination. (Mitt Romney ultimately took the Republican party's overall presidential nomination that year.) This near-perfect track record of selecting the GOP's ultimate presidential contender combined with the state's diverse mix of conservatives makes the Palmetto State a huge win for Trump and his supporters.

Gage Skidmore / Flickr - flickr.com

"The Republican electorate and leading Republicans have really prided themselves on being a bellwether on the Republican side," said Professor Gibbs Knotts earlier this month to the Boston Herald. "It’s sort of one that sends a different message sometimes than Iowa and New Hampshire."

Digging even deeper, we can see specific counties, in which a Trump win is key, on this map:

Religion News Service - religionnews.com

Analysts have selected these locations based on their historic rates of predicting the GOP winner. For the "establishment counties," ones in which a victory indicates who is most likely to be selected as the GOP nominee for the general election, Trump has taken one of three counties. (Meanwhile, Rubio is leading in Richland and Charleston County.)

Moving over to the "bellwether counties," Trump is predicted to win all five: Pickens, York, Kershaw, Sumter, and Horry. And with a Trump win overall for the state, this is to be expected since these counties usually determine the direction the state goes as a whole.

Where the South Carolina primary gets especially interesting, however, is the evangelical vote.

Religion's role in the South Carolina primary

More concerning to the Republican party are the "social conservative counties" indicated on the map. According to Tobin Grant of Religion News Service:

"These counties are must-win areas for Ted Cruz and any other candidate needing the support of evangelical voters. [...] If Cruz doesn’t do well in these counties, then he is in trouble."

In a race pitting Trump head-to-head with two evangelical candidates in a state noted to be far more conservatively Christian than either Iowa or New Hampshire, the New York businessman should be the least appealing of the candidates. Ted Cruz is the son of evangelical paster Rafael Cruz, and speaks about God and Jesus frequently on the campaign trail; Marco Rubio fits a similar mold.

But despite evangelical and born-again Christian voters making up as much as 74 percent of the electorate in South Carolina, based on early polls, Trump still came out the victor in the state. And he appears to be locking up all of the "social conservative counties," too.

This wider than expected appeal for Trump may indicate that he speaks to a wider swath of conservatives than the Republican mainstream has predicted for the political outsider, making him potentially more dangerous — and possibly harder to overcome for the party's establishment as primary season pushes onward.

But is it that simple?

AP/John Bazemore - apimages.com

But some experts still think it's far too soon to hand Trump the GOP nomination, like 538.com's Nate Silver.

According to Silver, South Carolina "looks about halfway in between" New Hampshire's and Iowa's outcomes for Trump, one of which was a heavy 20-point victory while the other was a loss for the candidate. He points to the fact that Rubio has inched up on Cruz in South Carolina and moved ahead in the view of some establishment voters. (This may be supported by his victory in Richland County, the only win taken away from Trump among the counties identified as key indicators in the state.)

One thing's for certain; it's a three-man race for the GOP nomination. And the candidate who was supposed to fade away by now has a comfortable lead.