The California redistricting ballot measure passed Tuesday with overwhelming support, but sources who worked on the campaign say it started off looking like a dangerous gamble.

Politico spoke to more than 20 campaign strategists, politicians, activists and others involved with Proposition 50 about the decision to roll the dice on a measure that started with just 38 percent support for Gov. Gavin Newsom's plan for allowing the legislature to redraw the state's congressional maps.

"A loss here would reverberate well beyond Sacramento: Trump could point to California — the state that sued, defied and mocked him — as proof that even a blue-state bulwark was no match for his drive to rejigger the midterm playing field, while Newsom would own a massive whiff against his favorite foil," Politico reported. "It would be the Fox News chyron Democrats most fear: 'TRUMP BEATS CALIFORNIA.'"

The plan started off as a bluff to force Texas Republicans to back down on their own plan, pushed by President Donald Trump, to redraw their own maps to rig next year's midterms in favor of GOP candidates, and that initial poll warned of a humiliating loss for Newsom and a potential drag on Democratic congressional candidates – but it turns out they were simply asking the wrong question.

"Paul Mitchell, a data expert who was busily fashioning new district maps for the congressional delegation, had put his own poll in the field," Politico reported. "He tested a hypothetical ballot measure that would hand redrawing power back to the Legislature but he, in his words, 'wrapped the redistricting in a reform burrito' — adding language that emphasized the effort would be temporary and only apply if Texas redrew its maps while affirming California’s support for national nonpartisan redistricting."

"The results stunned him," the report added. "Nearly 80 percent of respondents supported independent redistricting and, two questions later, roughly the same number backed new, politically-motivated maps."

Mitchell is not a member of the governor's inner circle, so he showed his results to longtime Newsom pollster David Binder, and the governor's team added another crucial change by putting the proposed maps themselves on the ballot.

"With the modified proposal in place, Binder conducted a second poll where the measure got 52 percent support — a marked improvement from the sub-40 percent result earlier that month," Politico reported. "For many Democratic voters, reservations that 'two wrongs don’t make a right' were suddenly subsumed by a hunger to sock it to the president."

Another senior Newsom adviser, Sean Clegg, added a final touch – having the Legislature designate the measure as Proposition 50 – that proved highly effective in getting the measure approved.

"A ready-made campaign slogan — A yes vote on Prop 50 would protect elections 'in all 50 states' — was now enshrined in law," Politico reported. "It was the earliest glimpse of the nationalization strategy that would undergird every piece of campaign messaging."