Thread by @NateSilver538

We've got a thing set up to anticipate how bounces from early states will affect national polls. Here's what it says the polls would look like nationally if all candidates exactly hit their current IA polls with Buttigieg winning IA

Biden—21%
Buttigieg—21%
Sanders—15%
Warren—13%

Just for fun, here's what it says what national polls look like post Iowa if Bernie wins Iowa with 25% of the vote, followed by Buttigieg (22%), Biden (17%) and Warren (13%):

Sanders—27%
Biden— 21%
Warren—14%
Buttigieg—12%

Anyway, we'll talk more about this stuff later. But one basic intuition is that Biden would probably indeed prefer Buttigieg to win Iowa rather than Sanders/Warren, because Sanders/Warren are stronger nationally and would be more likely to knock Biden out of 1st after an IA win.