Challenged by Old Allies, Teachers" Unions Court G.O.P. The strike by public school teachers in Chicago this month drew national attention to a fierce debate over the future of education and exposed the ruptured relationship between teachers" unions and Democrats like Mayor Rahm Emanuel. Over the past few years, even as Republicans have led efforts to thwart unions, lawmakers previously considered solid supporters of teachers" unions have tangled with them over a national education agenda that includes new performance evaluations based partly on test scores, the overhaul of tenure and the expansion of charter schools. As these traditional political alliances have shifted, teachers" unions have pursued some strange bedfellows among lawmakers who would not appear to be natural allies. In Illinois, the top two recipients of political contributions from the Illinois Education Association through June 30 were Republicans, including a State House candidate who has Tea Party support and advocates lower taxes and smaller government. William Seitz, a Republican state senator in Ohio who is a member of the American Legislative Exchange Council, a conservative business-backed group, has received more money this year from the Ohio Education Association than from any other donor. Teachers" organizations in Georgia and Texas have also donated to numerous Republicans. In all, teachers" groups donated $1.23 million to Republican state candidates through June 30, according to the National Institute on Money in State Politics. While donations to Democrats still far outweigh contributions to Republicans, the proportion of union money going to Republican candidates this year, just over 8 percent, has doubled since the last election cycle, according to the institute. In some states, the increase has been steeper. In Ohio, the proportion of contributions to Republicans jumped to more than 21 percent this year from less than 1 percent in 2010. Similarly, in Illinois, where 16 percent of donations went to Republicans in 2010, the proportion has increased to 22 percent. "The notion that just because you're a Democrat" you can take the teachers" unions for granted has changed, said Jim Reed, director of government relations for the Illinois Education Association. As teachers grapple with a reform agenda backed by hedge funds and large philanthropic donors and championed by the Obama administration as well as some conservative Republicans, the unions are navigating a delicate political landscape where they increasingly pursue friends in unlikely places. "Instead of reaching across the aisle to find support for increased funding for public education," said Richard W. Hurd, a professor of labor studies at Cornell, "they are reaching across the aisle for people who are not sold on the idea that charter schools are good, or that testing should be used for all teacher evaluations, or that teachers should lose job security." Such cross-party alliances have attracted the scrutiny of advocacy groups that unions have criticized for pouring money into the campaigns of candidates who support easing limits on charter schools and abolishing teacher seniority rules. Students First, the group run by Michelle A. Rhee, the former schools chancellor in Washington, provided The New York Times with a list of candidates who had received campaign donations from teachers" unions, which The Times has independently verified. Students First has contributed nearly $640,000 to Republicans in this election cycle, including money to some candidates who hold right-wing views on issues like abortion and same-sex marriage. The group, one of several that have contributed to candidates who support their education agenda, has also donated almost $1.4 million to Democrats. Tim Melton, legislative director of Students First, pointed out that many of the state candidates they support are members of the American Legislative Exchange Council, an organization that the American Federation of Teachers and the National Education Association have condemned for its education agenda, which includes vouchers, charter schools and test-based evaluations. "I'm greatly surprised that they would attack us ferociously for something they are doing themselves," Mr. Melton said. Union officials say they are just being practical. "It doesn't do a whole lot of good to shut out the Republicans who at least have the potential to be friends of the public schools," said Clay Robison, a spokesman for the Texas State Teachers Association. The teachers have also courted Republican lawmakers willing to go against their party to support issues like collective bargaining. In Ohio, Mr. Seitz was one of just six Republicans who voted against a bill that would have restricted the bargaining rights of public sector unions and eliminated seniority-based layoff protection for teachers. In a statement, the Ohio Education Association, which has given $11,450 to Mr. Seitz this year, cited his willingness to "listen to our positions on collective bargaining."