Tomorrow night marks the only Republican debate scheduled before the crucial South Carolina primary.

Donald Trump has all the momentum going in; Senator Ted Cruz (R-TX) is considered a strong challenger; Senator Marco Rubio (R-FL) faces a steep comeback after imploding in New Hampshire; former Florida Governor Jeb Bush continues to squawk about his supposedly revivified campaign; Ohio Governor John Kasich will put in a showing in South Carolina, but has already largely conceded the primary; Ben Carson is hanging on for no apparent reason other than to grow his database.

The only poll out of South Carolina following New Hampshire shows Trump with a commanding lead, clocking in at 36.3 percent; Cruz follows with 19.6 percent, then Rubio with 14.6 percent, Bush with 10.9 percent, Kasich with 8.7 percent, and Carson with 4.7 percent. Just 5.2 percent of voters say they’re undecided at this point. This means that barring a catastrophic collapse in South Carolina over the next week, or a massive coordinated attempt to consolidate the so-called establishment lane, Trump has a prohibitive lead.

The next primary state, Nevada, holds its caucus on February 23, just days later; then it’s on to the SEC Primary, where the following states are up for grabs: Alabama, Alaska, Arkansas, Colorado, Georgia, Massachusetts, Minnesota, Oklahoma, Tennessee, Texas, Vermont, and Virginia; a few days after that, we get Kansas, Kentucky, Louisiana, and Maine.

So, here’s where each candidate stands and what he must do tomorrow night to maximize the chances at electoral victory.

Donald Trump: Trump is the clear frontrunner at this juncture. If he wins South Carolina, he most likely pulls out Nevada too – the only polls from that state are old, but show Trump with a massive lead. If he has won three of the first four primaries heading south, he could run the table. All the polls from the March 1 states are too old to tell us much, but most of them have Trump way out in front: Trump +21 percent in Alabama; Trump +4 in Alaska; Trump +9 in Georgia; Trump +5 in Oklahoma. He’s close in a bevy of other states, including Texas, where he trails Ted Cruz by five percent as of late January. In the debate, Trump will likely be attacked on two fronts: lack of conservative values, and non-Christian values. He’ll fight back against Cruz on the Christian values point by going personal, driving home Cruz’s lack of charitable giving and accusing him of un-Christian campaigning, a tactic that seemed to work decently given the tacit help of Carson in New Hampshire. On the conservatism point, look for Trump to concede that he’s not doctrinaire, and claim that he’s willing to do what’s best for the American people regardless of ideology. He already previewed that claim this week. Given that Trump’s voters are the least ideological of any major candidate, that may bring him a win. Nate Silver currently has Trump at a 60 percent chance of winning South Carolina; if we ignore endorsements, that number rises to 72 percent.

Ted Cruz: Cruz is highly competitive in some of the upcoming southern states: he leads Trump in the most recent poll of Arkansas, for example, with Trump and Rubio four points back; in Texas, he leads Trump by five as of late January. But he’ll need to show something more than Iowa when we hit SEC Primary, or Trump will likely maintain his lead. His best shot here is to pound away at Trump for his non-Christian viewpoints and behaviors, as well as for his dismissal of conservatives. Fully 65 percent of voters in the South Carolina primary will be evangelicals, and Cruz dominates with such voters. The key for Cruz: do not play defense against Trump. The minute Trump goes on offense, Cruz must go right back at him. If he covers up, Trump walks away the winner.

Marco Rubio: Rubio still clings to the reed-thin hope that he will be able to finish strong in South Carolina and then buck history by winning just enough primaries to last until Florida and the winner-take-all states. It’s not impossible. He polls well in states like Minnesota and Colorado, and he hopes that Cruz will win enough states to hamper Trump while not winning enough to become the viable alternative. All this relies on him not collapsing in South Carolina. Right now, he’s running too close to Jeb! – so look for him to go on offense against Bush. He’ll have to overcome that burden of a historically bad gaffe in the last debate. The smart move would be to make a joke about it up front.

Jeb! Bush. Jeb! knows that this is his best opportunity to knock Rubio out of the race, grab the establishment mantle, and perhaps even compete in some of the southern states. To do that, he’ll need to pound Rubio as a lightweight incompetent. Oddly, he’s still pushing against Trump, which makes little sense given that he has no chance of dragging Trump down or raising his own poll numbers by bashing Trump – not a single Republican has gained in the polls by attacking Trump, particularly Jeb!.

John Kasich. Kasich’s hope is the same as Jeb!’s, but he can wait for Jeb! and Rubio to take each other out – he has no interest in winning South Carolina, and isn’t even campaigning there. He’ll look to sit out the fight, hope for a surprisingly strong finish, and then cruise into Minnesota, Massachusetts, Vermont, and Maine for big wins in a couple of weeks. If he then picks up Ohio, while Cruz and Trump trade punches, he hopes for a brokered convention where he becomes the establishment pick.

Ben Carson. Carson’s only in the race for the email list at this point. His campaign is in shambles, but he’s still raking in cash via his email operation. He wants to stick around as long as possible – and he understands that his best bet is to attack Cruz using his Christian credibility. That makes him Trump’s natural ally here.

To sum up: Trump has all the advantage here. Cruz took him down in Iowa once. He’ll have to do so again to prevent Trump from going on a major run for the next three weeks. Marco Rubio will have to fight to keep his campaign alive. And Jeb! Bush’s ego play will continue to muddy the waters, making it nearly impossible for anyone except Trump to win enough delegates before the convention.

Ben Shapiro is Senior Editor-At-Large of Breitbart News, Editor-in-Chief of DailyWire.com, and The New York Times bestselling author, most recently, of the book, The People vs. Barack Obama: The Criminal Case Against The Obama Administration (Threshold Editions, June 10, 2014). Follow Ben Shapiro on Twitter @benshapiro.