WASHINGTON — There are many reasons thousands of teachers traveled across the country to protest in front of the White House on Saturday — including to oppose charter schools, to fight for equal funding for poor schools, and to have more say in public education policies.

But at a noisy rally starting at noon under soaring temperatures, their message boiled down to one point, which was summed up by the sound check before the first speaker took the stage: Tap. Tap. “No testing, no testing, 1-2-3.”

The assembled teachers, education advocates and parents vented a frustration they said has been building since the passage of the No Child Left Behind law in 2002, which made standardized testing the centerpiece of a school reform agenda championed by George W. Bush.

“We had reason to believe from his campaign promises that (Barack Obama) was going to reverse the damage that this law has caused,” said Jonathon Kozol, a public education activist and author. “He has betrayed us. … That’s why we are here today.”

The White House invited some of the organizers, who said 5,000 showed up Saturday, to speak with education policy advisers on Friday, but the organizers turned down the offer, saying they would be willing to meet after Saturday’s march.