The best thing about holding what might be a repugnant brawl of a presidential debate in Las Vegas?

It’s hard to shock the locals.

Sin City is where Mike Tyson decided to take a chunk out of Evander Holyfield’s ear and, about a mile away, where Tupac Skakur found himself on the wrong side of a drive-by shooting.

Fortunes have been won and lost at the city’s gambling dens – granted, the stakes never as high as the presidency. Others came to Las Vegas and simply vanished (to quote Joe Pesci from “Casino”: “A lot of holes in the desert, and a lot of problems are buried in those holes”).

So what to expect in this, the final of the three 90-minute debates featuring Donald Trump and Hillary Clinton?

Third and Long For Trump. In football parlance, which would seem appropriate since Las Vegas seems destined to land the Oakland Raiders, it’s third and long for Donald Trump when he walks onto the UNLV debate stage with Hillary Clinton on Wednesday night.

Only, for Trump, there is no fourth down in this election.

Once debate night ends in Las Vegas, the candidates have just 19 more days to campaign. It’s Trump’s last clean shot at the electorate unless he plans to do a longer infomercial, as did Barack Obama in 2008 when he ran a 30-minute spot on the Wednesday before Election Day.

Trailing in the polls and in desperate need of altering the campaign’s narrative from something other than his past and personality, the stakes couldn’t be higher for Trump.

So high that perhaps he considers . . .

Re-Rigging The “Rigged” Talk? It’s been Trump’s rallying cry throughout the campaign, the notion that any and all things are “rigged” – the economy, the political system, a judicial system that didn’t prosecute his opponent.

And now, his claim that the election is a con job.

Trump’s latest accusation has been good for media attention. But at this late point in the election, perhaps it’s time to shift focus to what voters crave in what, theoretically at least, is a change election.

Since May 2015, two of my Hoover Institution colleagues have conducted a tracking poll of 5,000 voters. What’s remained consistent throughout: the economy trumps all over issues (pun intended).

If Trump’s smart, he takes every chance he gets to talk about stagnant wages and job insecurity. He could apply the “are you better off” standard to a host of other topics: foreign policy, national debt, racial discord and, last but not least, Obamacare.

This won’t be easy for Trump. The WikiLeaks gusher of Clinton campaign emails is a tempting subject to keep raising. But at this late point in the contest, one suspects that voters have pretty much settled on Clinton character issues.

What’s Hillary’s Game? We’re assuming Trump spends the night on the attack. Hillary Clinton’s approach: that’s a more complicated game of chance.

Let’s put this in Vegas terms – roulette, to be precise. Hillary could put all of her chips on a single spin – say, an angry spiel against Trump for everything from dredging up her husband’s past to the allegations that Vladimir Putin is trying to put his thumb on the election’s scale via WikiLeaks.

Her second and more conservative strategy (like playing a color or a corner): pick her moments to lace into Trump, but otherwise stick to what worked well for Clinton in the first debate when she smiled and let Trump run his course.

Should Clinton spend the evening as the most passive of debaters, riding out the clock and sitting on a lead she thinks is impermeable? Forget roulette. She’s now playing the nickel slots at New York-New York: slow, boring, and not much of a payoff.

A Moderating Influence. Posing the questions and handling the ebb-and-flow: Fox News’ Chris Wallace. His choice of topics: debt and entitlements, immigration, economy, Supreme Court, foreign hot spots, fitness to be president.

Wallace has a low bar to clear. NBC’s Lester Holt, the first debate’s moderator, was criticized for lax management.  CNN’s Anderson Cooper and ABC’s Martha Radditz, in charge of the second debate, suffered from moderatus interruptus. In the vice presidential debate, CBS anchor Elaine Quijano also interjected herself too often.

To give you an idea of what to expect in Vegas: Clinton appeared on Wallace’s Fox News Sunday at the end of July, after she was her party’s nominee; here’s Trump, from back in April.

Watch those videos and two things are apparent: Wallace is good at making interviewees uncomfortable, regardless of their persuasion: Clinton is smart to devote five days to debate prep.

Non-Debate Winners. Pop quiz: what do Utah and Vermont have in common other than open space and good skiing?

Answer: a chance for political mischief on Election Day, which hinges in part on the outcome of this debate.

In Utah, independent candidate Evan McMullin is a surprise second or a strong third, depending on various polls. Either way, it’s impressive given that he only qualified for the Utah in August. Should McMullin spring an upset, that’s six electoral votes Trump can ill afford to lose (the LBJ landslide in 1964 was the last time Utah didn’t go to a Republican).

As for Vermont, the question is whether Bernie Sanders could receive enough write-in support to win that state’s three electoral votes.

Vermont is one of seven states that count all write-in votes. Thirty-four other states count write-in votes, but only if the individual has filed papers with the state.

Why this is relevant? In a race where no candidate receives 270 electoral votes, the contest goes to the House of Representatives. There, the state delegations choose from the candidates with the three highest totals of electoral votes.

But in order what someone other than the two parties’ nominees to win a state, Clinton and Trump will have to take this election to a new low in their final debate – lower even than the current daily drip of alleged Trump sexual aggression and Clintonian wheeling and dealing.

Fear and loathing in Vegas, indeed.