The Associated Press examined political contributions over a 10-year period by the people who have been major contributors to advance school choice measures such as public charter schools and programs to use taxpayer funding to pay for private school tuition.

Some key findings:

Forty-eight individuals or married couples donated at least $100,000 from 2000 to 2016 to support statewide ballot measures advocating for the creation or expansion of charter schools or taxpayer-funded scholarships that can be used for K-12 private school tuition.

Those contributors account for more than three-fifths of funding to support the ballot measures since 2000.

The support from those contributors totaled nearly $64 million, nearly equal to the amount all opponents of the measures reported spending.

Despite the proponents’ spending, voters rejected seven of nine statewide school-choice ballot measures.

The contributors also are major givers to officeholders, candidates and causes. They donated a total of nearly $225 million from 2007 through last year. The biggest portion of their contributions went to candidates, party and general ideological political action committees.

Their spending was roughly even over that period on school choice causes, other education measures that were not specifically advocating for school choice, and causes that are not linked directly to education.

Teachers unions, which represent 4.5 million employees, reported giving about 21/2 times as much to political campaigns and committees as the 48 individuals and couples gave over the 10-year period.

The wealthy school choice advocates also put millions into nonprofit groups that advocate and fund school-choice measures.

The school choice advocates generally support public charter schools, which are run by different rules than traditional schools and often fall outside the oversight of local school districts. But their views diverge on the role of vouchers, which use taxpayer money to pay tuition at private schools. Still, the dividing lines are not always neat: Some contributors who say they oppose vouchers have funded groups that support them.