First Lady Michelle Obama’s job approval ratings have risen as more Americans conclude she is not revolutionizing the role of president’s wife, a new poll suggests.

The Marist poll released Tuesday shows 68 percent of Americans have a favorable opinion of Michelle Obama; it’s 53 percent among Republicans, which still makes her better received across partisan lines than her husband.

As for whether she’s doing well at the flexible and largely ceremonial job of first lady, 57 percent of Americans said yes. That’s up from March, when 52 percent rated her performance as good or excellent.

The shift comes as 46 percent of Americans have concluded she’s not changing the role of first lady at all, up from 31 percent who answered that way when asked in April.

The Marist survey also reveals the big racial divide in Michelle Obama’s job approval ratings. Among African-Americans, 80 percent rated her performance as excellent or good, while 70 percent of Latinos and just 52 percent of whites felt that way.

Back in the spring, one in five Americans said they weren’t sure how Obama, the first black first lady and a Harvard-trained lawyer and former hospital executive, would change the role of first lady. In the intervening months, she’s used her public appearances and remarks to emphasize healthy eating and women’s challenges in balancing work and family life, to talk about her young daughters, and to reach out to military families along with Vice President Joe Biden’s wife Jill. Michelle Obama has not taken a public role in the controversial health care overhaul effort.

Today, just 7 percent of people are unsure of how she’ll influence the job description of first lady. Those who said she’s changing the job for the better has dipped as well, from 44 percent to 37 percent. The Republican-driven sentiment that she’s changing the role for the worse rose from 4 percent to 10 percent.

The Marist poll surveyed 1,034 U.S. residents by telephone on Dec. 2-3 and Dec. 7.