The upcoming Democratic Primary debates could have an odd effect. [View all]

[MineralMan]

A lot of people who support candidates who have low polling numbers are counting on the debates to shift some people to their favorites. That could easily happen, if those candidates turn in a great performance in the debates.

But, here's the thing: Where will those preferences come from? If they come from the current second place contenders, that will have a negative effect on those contenders attempts to get closer to Joe Biden. It could drop some (or all) of those second place hopefuls under the 15% threshhold and knock them right out of the delegate count in some or most states' primaries.

That's the risk of having 24 candidates in a primary race. Every vote that moves comes from another candidate. Here's what can happen:

Let's say there are 23 candidates, plus Joe Biden, who starts out with a substantial lead in the polls. Will his poll numbers shrink? Probably not much, if any. In fact, he could pick up a few point from the debates. Suppose, just for grins, that all 23 other candidates end up earning enough support to get a couple of percentage points in the polls. At a minimum, that would add up to 46% of people supporting a candidate other than Biden.

But, here's the kicker: It could also mean that none of the 23 had 15% of support or higher, except Joe Biden. If that held through the actual primaries, Biden would end up with all of the delegates at next summer's nominating convention.

Of course, not all 23 will end up with 2% in the polls, but you can see what might happen. If nobody ends up with 15% or more, it's game over, and Biden takes it all.

So, choose wisely if you want someone other than Biden as the nominee. Pick a candidate who might win more than 15% of support. Be strategic with your preferences. It could matter a great deal.