There is differences of opinion about what the term “contested convention” means.
It is a possibility that neither candidate will win enough pledged delegates before the Democratic convention to win the nomination outright. That is because there are a large number of super delegates. In fact, if it were not not for the super delegates, with only two candidates in the race, a contested convention would be mathematically impossible. Either Hillary Clinton or Bernie Sanders would lock down the nomination before the convention.
Here the math:
There are a total of 4046 pledged delegates
Number needed to the win most pledged delegates before the convention = 2023 (half of 4046 +1)
But there are 719 super delegates
That raises the number of total delegates to 4765 (4053 + 483)
Number needed to win the most to total delegates before the convention = 2383 (half of 4053 rounded up)
Right now given that all Democratic delegates are awarded proportionally (there are no winner take all state contests) Hillary holds a commanding lead in pledged delegates: 1,289 to 1,038
Addition pledged delegates for Hillary to win most pledge delegates: 734 (2023 – 1,289)
Addition pledged delegates for Hillary to win the nomination before the convention = 1094 (2383 -1289)
The math works out this way because the super delegate aren’t considered until they vote on the first ballot in the convention. So as you can see it will be much harder for Hillary to lock up the nomination before the convention than to simply win the most pledged delegates.
There are a 1719 pledged delegate left to be won so Hillary needs only 42.7% of those delegates to win the most pledged delegates. However, she needs 63.6% of these to lock down nomination before the convention.
I certainly believe that Hillary will win the most pledged delegates – that should be easy. I also believe she will probably will lock down the nomination before the convention begins, but there is a possibility that she will not.
If Hillary has the most pledged delegates going into the convention, but has not won the nomination yet, some are saying it will be a contested convention. That’s because it would be theoretically possible for the Sanders’ campaign to “flip” enough of Hillary’s super delegates to their side to give Bernie the nomination.
However, everyone knows that isn’t going to happen, regardless how much the Sanders campaign talks about it. If Hillary wins most pledged delegates going into the convention, which is almost a certainty, there is no way that Hillary’s 469 super delegates are going to desert her for Sanders and she will win on the first ballot. That means that Hillary will almost certainly win on the first ballot. In fact I would expect most of the remaining uncommitted super delegates to vote for Hillary on the first ballot as well.
So those talking about what I would call a “true contested convention” are clueless. In my book a convention is “contested” only if there isn’t a winner on the first ballot and most of the pledged delegates are released from their pledges. That it isn’t going to happen at the 2016 Democratic National Convention.