John Kerry (search) canceled his scheduled speech Tuesday to the National Education Association (search) in order to meet with his new running mate, leaving thousands of teachers without the opportunity to hear from the Democratic presidential contender a day after endorsing him.

Word spread quickly among the NEA delegates that Kerry would not be coming to their annual meeting in the afternoon. The Massachusetts senator revealed earlier Tuesday that North Carolina Sen. John Edwards (search) would be his vice presidential candidate, and the two planned to meet in Pittsburgh later in the day.

NEA President Reg Weaver acknowledged he was angry, but he said it would not distract the nation's largest union from its business. He kept his cell phone on the podium in front of him as the convention resumed in case Kerry called to reschedule.

"There will be nothing that will be so disappointing that it will take us away from what we need to do for the rest of the year," Weaver said, referring to the union's drive to raise membership, get more federal money behind education and close the achievement gap between white and black students.

Some 9,000 NEA delegates on Monday gave Kerry a slightly smaller vote of support — 86.5 percent — than the 88 percent Al Gore got and the 91 percent Bill Clinton got during their presidential runs. But Weaver said members are just getting to know Kerry and are "peaking at the right time."

The endorsement by the 2.7-million member union of teachers and other school workers put a headline on the NEA's campaign for more education spending and changes in the nation's far-reaching education law.

The union gives Kerry a large mobilizing force. The NEA will target its political staff in 15 swing states, going into schools to rally its members and helping sponsor a night of house parties to elevate education as a political issue.

In turn, a Kerry administration could restore the union's access to the White House and advance its agenda on issues such as reforming student testing and halting any federal drive for private-school vouchers.

Kerry offers many teacher-friendly promises the union likes, but he also proposes ideas the NEA long has opposed, such as paying bonuses to teachers based on how well students perform on tests.

At the heart of the political debate in education is the No Child Left Behind law that was championed by President Bush and supported by Kerry in 2001. It requires a highly qualified teacher in all core classes, expanded standardized testing, and public reporting of how well all major groups of students perform.

The union opposes several aspects of the law, from the special rules given to teachers in alternative training programs to federal spending that, while at record levels, falls well short of the maximum allowed.

Kerry says he supports changes, such as reducing a reliance on high-stakes tests in determining school progress, and enforcing graduation requirements he says Bush has ignored.

Bush, though, is credited with helping Republicans take a Democratic issue by making education a key part of his 2000 campaign and pushing through a law that demands more attention for the poor and minorities.