Krasno, a lecturer at New York's City College and Yale University, is chair of the Woman for Secretary General Campaign, launched in February last year to push for the election of the first female UN Secretary General.
While the group does not have a single preferred candidate, Krasno said Clark's low ranking in the Security Council polls was a surprise given her impressive performance in public aspects of the campaign, such as a panel chaired by al-Jazeera television.
She said she could not see what faults the Security Council might see in Clark, other than those wanting a Eastern European.
"We thought she would definitely be stronger. She was disappointed in the results, but she's still in the running, she's still definitely competitive and she should stay because who knows what's going to happen?
In a recent interview with the Campaign to elect a Woman Secretary General, Clark voiced some frustration over the "opaque" process of the Security Council and warned that Council members could not ignore the public process up to then.
"I think the transparent part of the process opened up a lot of expectations for a different kind of profile for Secretary General," Clark said. "The issue will be whether the more transparent process to that point actually results in a different kind of person being chosen."
Some have cited Clark's strength of leadership as potentially off-putting for some Security Council members who might want a more compliant Secretary General.
However, Clark said the problems the world was facing now required a different sort of leader. "When you look at the many crises the world is facing, the UN has to step up to this and it won't be done through low profile leadership.
"It will be done by those who have the skills to advocate, to lead, to exhort, to encourage, to maximise the soft power possibilities."
She said the Secretary General did not have 'hard power' - it had no Army to deploy.
"But I come from a small country that never had any hard power either, you use soft power - the power of your voice, the power of your office to engage people."
So far male candidates have dominated in the two straw polls and Portugal's Antonio Guterres topped both. The women with the most support were Argentina's Susana Malcorra and Bulgaria's Irina Bokova.
Since the last straw poll, outgoing Secretary General Ban ki-Moon has also publicly added his voice to calls for a woman to take over his role when he steps down at the end of the year.
Of the remaining 11 candidates, six are men and five are women.
