Tea party groups over the past few weeks have suddenly and successfully pressured Republican governors to reassess their support for a rare bipartisan initiative backed by President Barack Obama to overhaul the nation's public schools.

Activists have donned matching T-shirts and packed buses bound for state legislative hearing rooms in Harrisburg, Pennsylvania, grilled Georgia education officials at a local Republican Party breakfast and deluged Michigan lawmakers with phone calls urging opposition to the Common Core State Standards.

The burst of activity marks the newest front for the tea party movement, which has lacked a cohesive goal since it coalesced in 2010 in opposition to Obama's health care initiative.