If Biden jumps in (and that seems likely), the Dems could have a good reason to dump Hillary.
If the Dems do dump Hillary, I think the media might turn on the Jebster. The main reason they are pushing Hill and Jeb is the Clinton-Bush match-up, reminiscent of 1992.
Without one of the contenders, the Clinton-Bush match-up doesn’t happen and Jeb doesn’t bring much to the table by himself — except for the Bush name for the Dems to run against.