ATLANTA: A day after making a $51 billion education initiative the centerpiece of his State of Union address, Bill Clinton was in Georgia drumming up support for a key part of his plan: college tax credits aimed squarely at the middle class. Under Clinton's plan, families making less than $100,000 can take either a $1,500 per student tax credit, labeled a HOPE scholarship, for each of the first two years their children attend college, or take up to $10,000 in tax deductions for post-secondary education and training. At face value, the tax break is good news to the nation's public colleges (average annual tuition $3,000) and 1,200 community colleges ($1,500). "It will provide strong support to pursue higher education, although it's difficult to project the impact on enrollment," says David Pierce, president of the American Association of Community Colleges. But many educators are worried that the plan's achievement requirements, which call for students to have a B grade average in their first academic year, could lead to grade inflation as financially strapped colleges try to keep the maximum number enrolled. The most persistent criticism is that since it takes the form of a tax credit, the initiative doesn't really help the poorest Americans toward higher education. "It's a middle-class tax break. That's something different than speaking about loans or scholarships," says David Markowitz of the American Council on Education, which represents 1,600 of the nation's colleges and universities. To blunt that criticism, the Administration last week shifted several billion dollars from HOPE scholarships to low-income Pell Grants, expanding the Pell program by 25 percent.