How Much Is Rubio Helping Trump? (P.S. You Too, Kasich)

INFOGRAPHIC: THE LARGE RED RECTANGLE REPRESENTS THE 150 DELEGATES AWARDED MARCH 8TH. THE BRIGHT RED SQUARE REPRESENTS THE SINGLE DELEGATE MARCO RUBIO WON OUT OF THAT BATCH. BY CONTRAST, RUBIO’S PRESENCE IN THE RACE DIRECTLY ALLOWED TRUMP TO WIN ANOTHER 13 DELEGATES. CREDIT: MIKE DUPUIS

UPDATE: Infographic now in HD high-definition. Our thanks to the artist, Mike Dupuis, for sending us the high-resolution file.

In my last post, I predicted that Rubio's continued presence in the race is not worth it, even in the extremely unlikely event that he wins his home state of Florida, because Rubio's running diverts votes from actually viable candidates... all to Donald Trump's advantage.

Unfortunately, on Tuesday March 8th, I was proven correct.  Rubio only won a single delegate, but at the same time Rubio gave Donald Trump more than a dozen.  Let's break it down.  We'll use the same assumptions as FiveThirtyEight, based on the Tuesday exit polls: if Rubio left the race, 25% of his voters stay home, 20% of the remainder go to Trump, and 80% to Cruz (split with Kasich if Kasich stays in).

We'll do the same for Kasich, while we're at it: according to the exit poll, if he left the race, 45% stay home, 66% go to Cruz (split with Rubio if Rubio stays in) and the remaining third go to Trump.

Fortunately, Tuesday's races were pretty simple, with some nicely uniform vote distributions and few weird Congressional district rules.  The results:

  MICHIGAN Actual Result w/o Rubio w/o Kasich Cruz Alone Trump 25 24 34 31 Cruz 17 18 25 28 Kasich 17 17 - - Rubio 0 - 0 - Trump Margin +8 +6 +9 +3 MISSISSIPPI Actual Result w/o Rubio w/o Kasich Cruz Alone Trump 25 25 25 22 Cruz 15 15 15 18 Kasich 0 0 - - Rubio 0 - 0 - Trump Margin +10 +10 +10 +4 IDAHO Actual Result w/o Rubio w/o Kasich Cruz Alone Trump 12 0 12 0 Cruz 20 32 20 32 Kasich 0 0 - - Rubio 0 - 0 - Trump Margin -8 -32 -8 -32 HAWAII Actual Result w/o Rubio w/o Kasich Cruz Alone Trump 11 11 11 11 Cruz 7 7 7 8 Kasich 0 1 - - Rubio 1 - 1 - Trump Margin +4 +4 +4 +3 TOTALS Actual Result w/o Rubio w/o Kasich Cruz Alone Trump Margin +14 -12 +15 -22 Trump Delegates Won on 3/8 73 60 82 64 You don't need me to explain this to you, folks.  If Rubio had dropped out of the race Sunday, Trump would have 13 fewer delegates than he has today, and Cruz would have won March 8th by 12 delegates (instead of losing by 14).

Kasich, because of how Michigan's allocation rules work, doesn't have a large effect on his own if he drops out. Likewise, there's still a thin case to be made that Kasich can help more than hurt with stopping Trump -- though, after Ohio finishes and the winner-take-all races begin in earnest, I have a hard time seeing it.

But if both candidates were out of the race, Cruz would have had a very good day Tuesday, making back nearly a quarter of his current delegate deficit with Trump in the space of just four states.  The Missouri, North Carolina, and Illinois races on March 15th -- the ones the media isn't paying much attention to because Ohio and Florida are The Most Important Things Ever In History -- are going to look a lot like this, but writ large: the presence of Kasich may not be so awful, but the presence of Rubio will be very damaging to the #StopTrump movement.

Rubio must get out now.  Not Tuesday.  Now.