Even if Klobuchar's exit helps Sanders win MN, it's probably good for Biden from a delegate standpoint. Here's why: A (pre-SC) poll in MN had Klobuchar at 29, Sanders 23 and no one else viable. In a scenario like that, Biden would get 0 delegates and Sanders 30+: 
Now let's say that Klobuchar, even after dropping out, still gets to 15%, with Biden moving up a little past viability and Sanders winning by double-digits. The actual delegate difference between Sanders and Biden is cut almost in half:
Now let's say Klobuchar misses the 15% threshold and it's just Sanders vs. Biden - and Sanders wins by 20 points. Even here, the actual delegate difference is Sanders +23 -- and improvement for Biden from when he was getting shut out
The bottom line for Biden is that he doesn't want to fall too far behind Sanders in the overall delegate count on Tuesday, Anything that gets him viable in states where he's been in danger of missing 15% (MN, MA, CO, CA) helps -- even if he's losing the state to Sanders.
