She's making bad arguments while doing so. Silly arguments.
Saying that 1968 and 1992 prove that it is common for the process to continue into June is ridiculous. In 1992, Tsongas had suspended his campaign in March, leaving Clinton well ahead of Jerry Brown. In 1968, the nomination process did not much reflect primaries--the eventual nominee entered no primaries. The convention really did make the candidate selection, with a large number of uncommitted delegates, with power-wielding delegation chairs. This method of insulating the nominating process from rank and file democrats led to some unpleasantness at the '68 convention, which is what led to the reforms implemented in 1972. The 1972 primary-driven process is still the basic template we user today.
But none of that really is all that important, because in '68 the incumbent president withdrew his candidacy after losing a primary to an insurgent. There's no way that wasn't going to be a messy process of selection, or that it would not go to the convention.
So this is a bad argument.
But she has a good one to make. The race is very close. It's closer than any nomination process since the primary system was put into place. Carter had a 600 delegate lead over Kennedy in 1980. And the superdelegates make no sense if they are not meant to arbitrate a close race.
Her case is a simple one. Her candidacy is as popular with the rank and file as Obama's is, certainly within the margin error of the arcane process involved. So, she can say, leave it up to them.
At the very least, she deserves to have her delegates at the convention, she can say. The convention is not just about choosing a presidential candidate. It is about, among other things, reviewing the nominating process.
If she had kept her focus on the delegates, she would not sound so, frankly, desperate and illogical as she tries to weave tales of electability and which states count.