Blocked by the Legislature, Governor Mitt Romney plans to appeal personally to the state Board of Higher Education today to pass his controversial plan to waive state college tuition for students with high MCAS scores, according to the board's chairman.

Romney's proposal for the John and Abigail Adams Scholarships would award free tuition at public colleges and universities, worth $1,700 a year, to the top quarter of scorers on the MCAS exam. Students scoring in the top 10 percent would receive an additional $2,000 cash.

Although Romney said the Adams Scholarships would help working- class families, a Globe analysis of juniors' MCAS scores showed that the school districts with the largest share of potential recipients are overwhelmingly affluent, suburban, and white.