This summer, a fired-up Kevin McCarthy vowed to personally lead the fight against California Democrats’ redistricting push, aiming to raise $100 million to help protect Republican lawmakers in his home state.

But in the final weeks of the high-stakes election, the former GOP speaker has fallen massively short of that mark, according to people familiar with the fundraising goal he set. That has required more direct involvement from both the White House and GOP leadership, those people said.

Republicans acknowledge that they always faced an uphill battle to defeat Democratic Gov. Gavin Newsom on the referendum, known as Proposition 50, in a state where registered Democrats outnumber Republicans by 4.5 million voters. But multiple Republicans told CNN that McCarthy and the groups involved in the campaign squandered a critical early window to craft a compelling message and raise the financial resources necessary to compete.

Now, even some senior House GOP leaders privately concede the measure is on track to pass, another Republican source said.

“I think it is an opportunity that is being wasted,” one House GOP lawmaker from California told CNN.

“A lot of people are frustrated … a lot of money could have gone into this,” the member said, noting that the fundraising is “nowhere near what normally happens in an election cycle.”

This lawmaker was among several Republicans who told CNN that they had been expecting a major influx of GOP cash that simply did not materialize.

Groups opposing Proposition 50 have spent a total of about $31 million so far on TV advertising while groups supporting the measure have spent more than $80 million, according to the media tracking firm AdImpact. That gap has grown over the last four weeks, over which the “No” side has spent just $3 million on ad time, while the “Yes” side has spent more than $40 million.

McCarthy’s committee was meant to ramp up its spending in the final weeks of the campaign, a source familiar with the “No” side’s thinking told CNN. But that spending didn’t materialize to the level Republicans hoped. The group, “No on 50 – Stop Sacramento’s Power Grab,” has raised just $11.4 million, according to recent campaign finance data.

“It’s not raising money at a time when it really desperately needs those resources,” the source said. “So, the prognosis for this specific campaign doesn’t look terribly good.”