Hillary Clinton joined the list of presidential candidates courting the AFL-CIO this week. Politico forecasted that she would focus on her co-sponsorship of the Employee Free Choice Act and her promotion of collective bargaining, but would face pushback on the Trans-Pacific Partnership (TPP). An early report from the Wall Street Journal quoted union leaders who found Clinton’s message “cautious.” They are concerned by Clinton’s refusal to take a position on the TPP, a key issue for labor and a polarizing topic within the Democratic party.

The day before, Mike Huckabee met for an hour with the AFL-CIO’s executive council, the only Republican to accept the labor federation’s invitation. The Washington Post speculates that Huckabee’s attendance will help him garner support among blue-collar union households, even if he knows he will not receive an endorsement from labor. During the meeting, Huckabee praised the AFL-CIO’s training programs, but prefers to defer to states on whether to pass right-to-work laws.

Right-to-work laws found another champion today: the Michigan Supreme Court. The court upheld a decision to preserve the state’s right-to-work law, passed in a 2012 lame-duck session without committee hearings or public input, amidst protests by thousands of opponents. The unions who brought the suit contended that only the bipartisan Civil Service Commission—not the state legislature—could set employment conditions for civil servants. But a 4-3 majority declared that the Civil Service Commission “never had the constitutional power to impose agency fees on workers, even before the right-to-work law existed,” reports the Detroit Free Press.

One group of Silicon Valley employees has unionized: shuttle drivers, who ferry workers to corporate campuses. Shuttle drivers for Apple, eBay, Yahoo, Zynga and other firms plan to vote this weekend on a new wage and benefits package. According to USA Today, the 160 drivers sought representation from Teamsters Local 853 after the union reached a new contract for Facebook drivers in February. The Teamers have been in negotiations with the drivers’ direct employer, Compass Transportation, for five months. The new contract may reflect a growing sense of corporate responsibility for outsourced labor, predicts law professor Alan Hyde.

Latina workers in Massachusetts earn only half of what white men performing those same jobs bring in, a University of Massachusetts Boston study finds. Although a gender wage gap persists across society, Latina women in low-wage jobs highlight that disparity. The Boston Globe reports on efforts by the city of Boston and the Massachusetts State House to narrow the wage gap, including considering prohibiting employers from seeking job salary histories, and requiring employers to provide equal pay for comparable work.