The points you just raised are dependent on a contested convention. Not on a clear majority outcome. The whole point of gaining a majority of delegates in the primary is that the delegates who pledged themselves to the also-ran don't matter jack doodly squat at an uncontested convention. They can stand up and pledge their support to Marco Rubio or Marco Polo- the majority rules. Now, within that majority may exist a group of bound delegates and a group of unbound delegates- the latter far outweighed by the former. And sure, there's presumably some wiggle room in that group of unbounds if you're looking for it. But my point still stands: bound delegates are bound delegates, and they're bound by state rules rather than party rules. Hell, they're currently bound by party rules as well (more on that in a second). Nothing in the wikipedia article you linked to disproves that. Here, I'll quote where the misunderstanding might have come about: That's per DNC custom. Per RNC custom: A majority of the unpledged delegates are elected much like the pledged delegates, and are likely to be committed to a specific candidate. Many of the other unpledged delegates automatically claim the delegate status either by virtue of their position as a party chair or national party committee person. This group is known as unpledged RNC member delegates. The process by which delegates are awarded to a candidate will vary from state to state. Many states use a winner-take-all system, where popular vote determines the winning candidate for that state. However, beginning in 2012 many states now use proportional representation. While the Republican National Committee does not require a 15% minimum threshold, individual state parties may impart such a threshold. The unpledged RNC member delegates are free to vote for any candidate and are not bound by the electoral votes of their state. Unpledged RNC delegates are free to vote for any candidates. Pledged delegates? Not so much. Now, this goes out the window in a contested convention. And there's one guy- one guy! Arguing currently that pledged delegates aren't actually pledged: http://dailycaller.com/2016/03/13/rnc-rules-comm-member-every-delegate-at-gop-convention-not-bound-on-first-ballot/ Side-note: I can't find reports of this from any reputable news source, so I have to take this whole memo with a grain of salt. Most reports, however, state pretty unambiguously that bound delegates are just that. Here's a horribly-designed website that lays it out in pretty granular detail: http://www.thegreenpapers.com/P16/R-Alloc.phtml Ctrl+f "bound" to navigate that trainwreck. Note that the rules state not only that delegates who ignore their pledge shall be penalized, but that their decision change won't even be recognized. Note that those rules are the 2016 rules. Applicable as of April the first of this year. That's uncontested. It's not a misconception, it's actually pretty clear as per current rules. Contested? Whole different ball game. Here's a helpful guide that isn't wikipedia: http://www.slate.com/blogs/the_slatest/2016/03/10/a_contested_republican_convention_explained.htmlThis is clearer to see in this example: Rubio won 169 delegates, and then dropped out of the race. So are those delegates forced to vote for him at the Republican Convention? Of course not. They are free to change their mind and vote for any other candidate.
Pledged delegates are elected or chosen at the state or local level, with the understanding that they will support a particular candidate at the convention. Pledged delegates are, however, not actually bound to vote for that candidate, thus the candidates are allowed to periodically review the list of delegates and eliminate any of those they feel would not be supportive. Currently there are 4,050 pledged delegates.
The Republican Party utilizes a similar system with slightly different terminology, employing pledged and unpledged delegates. Of the total 2,472 Republican delegates, 1,719 are pledged delegates, who as with the Democratic Party, are elected at the state or local level. To become the Republican Party nominee, the candidate must win a simple majority of 1,237 of the 2,472 total delegates at the Republican National Convention.