Supporters of charter schools, homeschooling and other forms of school choice are so used to fighting in the trenches against the state's muscular teachers unions that they often forget how much progress they've made in the last decade or so. Recent events have shown the degree of progress, even if they still face an uphill—and increasingly costly—battle.

The big news came from a local school-district race, although it wasn't just any school district but the second-largest one in the nation. Charter-school supporters won two school board seats (there's still some vote counting in one of them) in the massive Los Angeles Unified School District, and handily disposed of the union-allied board president. The race was followed nationally, and set the record for the most money spent on a school-board race in the United States, ever.

The total cost was estimated at $15 million, with charter supporters spending $9.7 million, according to estimates from the Los Angeles Times. Typically, choice supporters get eaten alive by the teachers'-union spending juggernaut. It's usually good news if our side can at least raise enough money to get the message out, but it's a shocker—in a pleasant way—to find the charter folks nearly doubled the spending of the union candidates.

Various reformers, including Netflix cofounder and Democrat Reed Hastings, invested serious money in the race. He donated $7 million to one charter group, the Times reported. Another top donor was former Los Angeles Mayor Richard Riordan, a moderate Republican, who spent more than $2 million. Once again, we saw that this was not some right-wing attack on unions. Victory didn't come cheap, but it's hard to understate the importance, from a reform perspective, of having a major school board run by a pro-charter majority.

LAUSD's school Board President Steve Zimmer led the board in March to make a controversial—and largely symbolic—vote in favor of one of the more noxious school-union-backed bills to get a hearing in the state Capitol. Some charter supporters say Senate Bill 808 could be the death knell for most of the state's charter schools, yet Zimmer's support for it appears to have badly damaged his re-election chances. That's another good-news event.

SB 808 is a brazen attempt to bring charter schools under the total control of local school districts, many of which are hostile to their very existence. According to the Senate bill analysis, "This bill requires all charter school petitions to be approved by the governing board of the school district in which the charter school is located, prohibits a charter school from locating outside its authorizer's boundaries, and limits the current charter appeal process to claims of procedural violations."

If educators wanted to create a charter school within any district in California and that district is run by a union-controlled school board that hates charters, then there would no longer will be any real workaround if the bill passes. That's because the bill would wipe out appeals to the county and state level, except for some minor procedural matters.

Furthermore, the bill would let school boards decommission or reject charter schools if they are a financial burden. As the 74 Million blog reports, "that argument could be made about any charter, as state funds follow students as they leave school districts." The bill allows the board to revoke a school's charter upon a variety of broad findings, including any improper use of funds or "sustained departure" from "measurably successful practices," or "failure to improve pupil outcomes across multiple state and school priorities…"

So, one instance of improper use of funds could shut down a school. Imagine if that standard were applied to the LAUSD itself, given its scandals. Charters succeed because they have the freedom to have a "sustained departure" from the failed union-controlled teaching policies. Under this bill, the core of their success could be cause for their shut down. And no school can always improve pupil outcomes in every category. These things take time, and measurements can be subject to interpretation.

In other words, the bill would place the fate of California's charter schools in the hands of those most committed to their destruction. Given that the makeup of school boards can change every election, it would destroy any security parents could have in these schools: one successful union board election could mean the beginning of the end for the school, as union-backed boards use these new "tools" to dismantle the competition.

But there is good news. The bill was recently shelved, turned into one of those two-year bills that is technically alive but going nowhere fast. The Democrats control the state Capitol and the California Teachers' Association arguably is the most powerful force under the dome, but many Democrats representing low-income districts aren't about to mess with successful charters.

In other words, charter schools have come into their own, and we're probably well past the point that the unions could so directly stomp them. They'll do what they can to harass and hobble them, but such frontal attacks remain symbolic. And the courts continue to have their say, and frequently end up siding with the charter-school movement.

For instance, in late April the California Fourth District Court of Appeal ruled in favor of Anaheim parents who want to use the state's parent-trigger law to turn a traditional public elementary school into a charter school. Under the trigger law, a vote by 50-percent of the student body's parents can force low-performing schools to change the administration or staff, or revamp themselves into a publicly funded charter with more teaching flexibility.

The school district was adamantly against the change and made various challenges to a 2015 court decision approving the trigger. This is another victory for charter schools in California, although it has to be dispiriting to parents who have to continually fight in the courtroom while their kids get older. It's been two years since the court approved changes at the school, which already has delayed improved education for two more class years.

But the court's decision is still encouraging news, as the cultural sands shift in favor of educational alternatives, especially for low-income kids.

California candidates already are lining up for the 2018 gubernatorial race to replace Jerry Brown, who has been friendly to charters. One of the candidates is Delaine Eastin. She's a close ally of the teachers' unions. In the early 2000s, when she served as the superintendent of public instruction, Eastin tried to essentially outlaw homeschooling throughout the state.

California's education code doesn't directly mention homeschooling. The state's compulsory education law mentions only an exemption for "children who are being instructed in a private full-time day school by persons capable of teaching … ." Homeschooling parents have long embraced a state-approved work around: They register as small private schools with their respective county boards of education.

Under Eastin's leadership, however, those homeschools were required to file with the state Department of Education rather than the counties. And then Eastin sent a letter to district officials explaining that homeschooling as it is generally understood (parents without a teaching credential who teach their kids at home) "is not authorized in California, and children receiving homeschooling of this kind are in violation of the state's truancy laws."

Yet I talked to Eastin recently and she said she recanted her position long ago after getting quite an education from homeschooling parents. She even described herself as a supporter of charter schools. As with everything, we must follow Ronald Reagan's advice for dealing with the Soviet Union ("trust, but verify"). But what does it say when one of the most dogged allies of unionized public schools now takes a position acknowledging the importance of parental choice?

It says that we're making progress. It's frustrating, plodding and expensive. But such progress should keep charter supporters encouraged as they head into the next round of battles.

This column was first published by the California Policy Center.