not flirting.

(BTW, as I understand it, 15% is per district)

Typically, yes, it is by district for most of the delegates. Statewide delegates, though, are governed by the 15% rule statewide. You have to look at the rules for each state to be able to make estimates in that state.

It's also important to look at the number of delegates each state sends to the convention when estimating results. That's why Super Tuesday primaries will weigh much more heavily than the first four primary states.

Sanders and Warren are both flirting with the 15% rule. The other candidates who are edging up are not near that percentage - yet. Being slightly above that percentage does not guarantee that you will stay there. As candidates drop out during the primaries, their supporters will shift to other candidates. Undecided voters, too, are going to play an important role.

Actual primary season is getting closer and closer. Then, we will begin to be able to see close estimates of delegate counts, although final results won't be known in many states until they hold their state conventions.

All candidates who get less than 15% of the vote are no longer relevant in awarding of delegates. Instead, the delegates are assigned based on the proportions of the votes for those candidates who receive more than 15%. That's where things get a little tricky as delegates are selected.

For example, let's say only two candidates in a primary election got more than 15% of the vote. Let's say, further, that one got 34% of the vote, while the other got 17%. Everyone else got less than 15%. What happens then is that the candidate who got 34% of the vote gets twice as many delegates as the one who got 17%. The final delegate count would be 67% for one candidate and 33% for the one in second place. Proportionality is the rule.

If more than two have over 15%, the same proportionality applies, with delegates assigned according to the proportions seen in the percentages of those over 15%.

There is also rounding going on if the number of delegates doesn't divide up evenly among the candidates in proportion. That's why it's difficult to immediately predict exact delegate counts after a particular election. Sometimes the math is somewhat complicated. That's especially true in district delegate allocations, where there are few delegates to be assigned.

In the end, the more candidates there are on the ballot, the less likely any one of them will receive a majority of the vote. By the same token, it's also more difficult for candidates to receive over 15% of the vote.

The 15% rule is designed to eliminate candidates from consideration to help ensure that someone goes to the convention with a majority of delegates. It's not necessarily completely fair, but it is necessary, politically.

No one's taken that lead consistently, much less advanced to join Biden as a first-tier candidate.

I expect you're right that Sanders' latest bubble, bubble toil and trouble will sink him again and raise Warren again.

And that 15% rule always gets me crossing my fingers. I want Sanders' "lock her up" delegates to have to rant from home, or at best along with the trumpsters outside the convention.