The lone holdout juror who helped force a mistrial in Lindsay Clancy‘s murder case is getting some serious financial backing … with a fundraiser supporting him already pulling in tens of thousands of dollars.

A GiveSendGo titled “Stand With the Juror” has raised over $70,000 toward a $100,000 goal as of Sunday afternoon … with organizers saying the money is intended to cover the juror’s security, attorneys and lost wages if he faces fallout over his role in the mistrial.

The fundraiser fiercely defends the unidentified juror who refused to join the other 11 in finding Clancy not guilty by reason of lack of criminal responsibility in the deaths of her three children.

Its organizer blasts the mental-health defense presented at trial and argues the holdout focused on what Clancy did rather than her postpartum psychosis diagnosis and medications.

The page also takes aim at Clancy’s defense team for asking the judge to remove the juror during deliberations … before declaring, “We’re not letting this slide.”

As we reported … Clancy’s jury deadlocked 11-1 earlier this month after more than 38 hours of deliberations, with the lone holdout refusing to acquit her by reason of insanity.

Several jurors have since publicly ripped the holdout … accusing him of ignoring reasonable doubt and being unable to point to evidence supporting his position. One juror also claimed the holdout mimicked the children’s strangulation during deliberations using an exercise band and water bottle.

Clancy’s attorney Kevin Reddington had asked the judge to boot the juror before the mistrial was declared … but the judge ultimately allowed him to remain on the panel.