Donald Trump wants to deprive his competitors of any oxygen. That’s why the former president is likely skipping next week’s debate in Milwaukee.

But it probably won’t work.

As presidential primaries have become more national in scope, debates have arguably been all that’s really mattered in the run-up to the early states. Candidates like Herman Cain, Newt Gingrich, Ben Carson and Pete Buttigieg surged in the polls after strong showings.

And Fred Thompson, Rick Perry and Beto O’Rourke stand as cautionary tales of hyped-up candidates who bombed on stage and saw their campaigns crumble months before voting even began.

The proof is in the numbers: Much of the movement in recent primary fights has been marked in time by the nationally televised debates. Candidates sink or swim based on their debate performances — and the first debate has often been the catalyst for the first real changes in those races.

Even if Trump doesn’t show, the debates will still command larger audiences than anything else the candidates will do over the next six months. So it’s an unparalleled opportunity for those seeking their breakthrough moment, like Tim Scott, Nikki Haley or Vivek Ramaswamy. And the peril for a once-hyped hopeful like Ron DeSantis if he doesn’t deliver is real.

Yes, Trump has a huge lead in the national polling at this stage — far larger than any of the six primaries we examine below — and a slightly-smaller-but-still-commanding advantage in the early states. But if he’s serious about skipping the debate, he risks being upstaged.

Here’s how the debates have mattered over the past few primary cycles:

2008 Republicans

RealClearPolitics leader on day of first debate (May 3, 2007): Rudy Giuliani +10.2

RealClearPolitics leader on day of second debate (May 15, 2007): Giuliani +7.5

Only 12 days stood between the first two debates of the 2008 GOP race, which also came extremely early in the election cycle. Thompson, the former Tennessee senator and actor, wasn’t yet a declared candidate. (This year, DeSantis, Scott, Pence and Chris Christie were not yet official candidates as of mid-May.)

Thompson wouldn’t take the stage until the seventh televised debate on Oct. 9, 2007. He entered the meeting at 20.2 percent in the RealClearPolitics average, good for second place behind Rudy Giuliani.

His freefall started soon after. Less than three months later, he was in the single digits going into the Iowa caucuses and dropped out in mid-January.

2008 Democrats

RealClearPolitics leader on day of first debate (April 26, 2007): Hillary Clinton +9.7

RealClearPolitics leader on day of second debate (June 3, 2007): Clinton +11.2

The primary wouldn’t end up going Hillary Clinton’s way, but the first debate in April 2007 helped cement her as the nominal frontrunner in the race for the Democratic nomination.

A weak performance from former Sen. John Edwards hurt the North Carolina Democrat: He entered the first debate at 16 percent but was only hovering around 10 percent by the candidates’ second gathering.

The most consequential debate moment came in the days before the New Hampshire primary, which Clinton would go on to win after losing Iowa to Obama. A strong performance, combined with Obama’s awkward “likable enough” moment, helped catapult Clinton to victory, despite pre-primary polls suggesting Obama was riding a wave of momentum out of Iowa.

A strong debate performance catapulted Hillary Clinton to win the 2008 New Hampshire Primary.