"I've read a bit about receiving a plurality of votes versus a majority and how things change from the first round of voting to subsequent ones.  Can you speak to this and also if Sanders changed his position from 2016 to the present?"

Sure, on the way it works at the convention is once they count the first vote if a single candidate does not have the set threshold of delegates from the primaries to be declared the outright winner (it's 1900 something delegates) then they can go to a second vote.

So, technically, using Sanders as an example, he could have 1900 delegates but that could leave him say 80 short of the outright winning total...if this were to happen another candidate that ran could throw their delegates into Bernie's pot but currently no candidate running has said they would do this, they all said on stage that they would prefer to go to the second vote and have the convention "brokered."

Let's be clear why they all said this, it currently looks like a foregone conclusion, barring some major event, that Sanders will end up with the most delegates by far but he may end up somewhat short of the 1900 whatever number that declares him outright winner. Normally in this case for the party to show unity the other candidates who have no chance of getting to this number would release their delegates to let them support the candidate that ended up with the most votes, support, and that has the delegate lead from the primaries. 

Here's where it gets tricky, the superdelegates become important only on this second vote now. Essentially all delegates previously pledged to a candidate through whomever won their states primary process are now released from their commitment to vote for the candidate that won their state's primary. Although they can choose to honor their states voting results they can also be talked into casting their vote for someone else.

So, if they can keep Bernie from winning the threshold number (1900 whatever) they can technically force this second vote and at this time they could put forth other names to be considered to be their nominee that then all the delegates at the convention would be asked to vote for until they have a winner. 

In this process all the superdelegates, 700 something of them, can now have a major effect on choosing the candidate because they can all throw their votes behind someone, say Bloomberg or Hillary, or Michelle Obama...whomever they feel is the best representative...and now you have a situation where whomever they chose would likely be very difficult to beat because these "party leaders" have thrown a 700 plus delegate edge to the candidate of their choosing. 

Obviously, all the candidates in the race right now hope it would be one of them but that's a problem because none of these candidates have shown an ability to win the primary process never mind win the general election. So, the feeling among these superdelegates is they would choose someone outside of these people...hence the list of names collected by the NY Times. 

OK, so that's the brokered convention deal, and so the party leaders are throwing around the idea that no candidate has to beat Sanders they just have to keep him from winning the 1900 something delegates so they can force the second vote at the convention and then all bets are off. They can then have a free for all fight on the convention floor to pick a candidate...but if they do this they are throwing out the entire primary process. Not very democratic and this would play right into Trump's claims that the Democratic party does not give a damn about the voting process...as they would be eliminating every vote cast during the primaries.

To be fair here, which I am into, this means this should not just concern and cause an issue with Bernie voters...it should cause an issue with any voter that went out to vote in the primary process...because they are telling you that was a waste of time and because we did not like how you voted...well...your vote does not count.

Bad idea...very bad idea. 

OK, part two, did Sanders change his position?

No, he did not. To understand this we have to look at what happened with the 2016 election. Doing so shows the crazed hypocrisy of the Democratic party leaders in this election. 

So, in 2016 the rules allowed the superdelegates to announce who they would be casting their vote for at the convention at the start of the primary process. So, they did, and because the party had cut a deal to be in the bag for Clinton...well...they mostly all announced they were voting for Clinton before a single vote was cast.  

The result of this was that everybody in the media reported as if Clinton was the winner of the primary process before it even started because she had a massive "superdelegate" lead in the race to 1900 whatever. So, they not only handed control of the DNC to the Clintons they handed her a big lead before the voting started. 

So, as the primaries began the media continued to constantly report Clinton's massive delegate lead which gave the impression that she was the sure thing winner before a vote was cast. This typically impacts the process because people are being told she has a lead that can't be surpassed so if you are going to vote...well...you are wasting your time voting for anybody but Hillary because she already has a massive lead on her way to the nomination. 

This is what Bernie and his people said was unfair and was not Democratic...and you have to admit they were quite correct. This was not a fair process and the superdelegates all voting for Clinton before any of us cast our votes was ridiculous. This was just the DNC attempting to assure Clinton the nomination because she was their chosen candidate. You might remember that I brought this up when you, Dan, and I were having drinks. I mentioned that hey, the truth is it is not our party. We can vote, we can contribute money, but the party leaders can choose their preferred candidate and stack the deck for that candidate...as they had done just that.

So, honestly, yes, the Russians did interfere for Trump in the 2016 election but the DNC interfered in the 2016 primary process in a massive way as well to make sure their nominee would be Hillary Clinton. You can count me as not happy with either of these situations. Honestly, the entire 2016 process was a joke if this country is supposed to represent the beacon of democracy for the world...because we basically pissed all over that in 2016.

So, the Democrats after their horrific loss to Trump did decide "We need to change some rules here." because going in the bag for Clinton backfired horribly. So, they did what Democrats do and formed a committee to make changes. The Sanders people or the progressive wing of the party did ask for representation on the committee and they were given some spots on it. So, what did Sanders/Progressives want? The elimination of the superdelegates and certainly their ability to do what they did in 2016 which was to announce who they were supporting before a vote was cast. 

Did they get that? No, they did not. The superdelegates did not want to go away. It was a coveted position that came with lots of perks so what they did was compromise and made the superdelegate's votes only important IF the first vote at the convention failed to produce a nominee. 

So, here's what DNC people, and Elizabeth Warren, argued Sanders supposedly did. He would not fold up his campaign and wanted to go to the convention with the delegates he had won in the primary process. He did make a bid to superdelegates to support him to no avail as that would never happen but he wanted to go to the convention not to win the nomination, he wanted to go to support a progressive agenda and policy. Because Sanders was close and if you subtract Clinton's superdelegates very close, he felt he should use the moment to promote progressive policies...which was the whole point of his 2016 campain. He did have a huge argument to do so as that agenda won 23 states and he had come out of nowhere to do it and showed what he was speaking about mattered to voters. 

However, as people charge Sanders with doing this they never mention how ridiculously unfair, intentionally, that 2016 process was. Because superdelegates announced their support for Clinton before votes were cast he should have been making an appeal to them not to do that and that at the very least superdelegates from the states he won should be casting their vote for him...that's fair.

Now what DNC people want to do is claim Sanders helped write these new rules, by this they mean there were progressives on the committee, but no he did not write the new rules and they now are attempting to use the fact they would not eliminate superdelegates and preserved their power on a second vote against Sanders. 

You can bet your ass, Peter, that if Biden won a plurality of the delegates going into the convention that they would scream from every rooftop that to "preserve unity" all the other candidates should release their delegates to Biden. 

Instead because it looks really likely that Bernie will easily do this that instead they will say "Sanders has declared war on the Democratic party."

I call them as I see them, and on this I definitely call bullshit.