What about this scenario?

[solarstorm]

Clinton refuses to announce her candidacy, but she's been running a quasi-campaign in order to attract media attention.
She hasn't felt certain for a long time about if she really wants to go into the primaries or if she's gonna bow out of politics.
In the end she has decided to yield the floor to her fellow Democrats.

The crux of the problem: No Democrat has dared to challenge her due to pointlessness.

1.) Would she really bow out under such a circumstance?

2.) If so, what would be the deadline to do so?

[solarstorm]

For the first time I've realized that it would be detrimental to the Democratic Party if no one dares to run against Hillary. If she dies or falls ill, she'll leave a vacuum.