Having worked with Elena Kagan at the Bill Clinton White House, I was inclined to see her as a political moderate, worthy of support as the best one could expect from the Barack Obama White House. But no more.

Thanks to the work of the Center for Security Policy Director Frank Gaffney and the writing of Andrew McCarthy of the National Review Institute, there has emerged a compelling reason to vote against Kagan's confirmation as a Supreme Court justice: Her support for Shariah Law while she was dean of the Harvard Law School.

Islamists are seeking to spread Shariah law by inducing American and European financial institutions to establish Shariah Compliant Funds in which their clients can invest. These funds follow the prescriptions of Shariah law in their investments. They routinely collect 2.5 percent of the principal of any investment annually for donation to charitable institutions, fine recipients of their investment 7 percent for transgressions of Shariah law (and donate the fine to charity) and only invest in projects compliant with the rules of Shariah.

Unfortunately, the decisions as to which investments are compliant and which charities receive their benefice are made by Shariah Compliance Boards appointed by the financial institution, typically including radical Muslim extremists. They routinely designate terrorist-linked entities to receive their charitable donations and also proscribe investment in any firm engaged in U.S. defense contracting on the ground that the contract could aid Israel.

Most major banks in the U.S. and Europe have established Shariah Compliant Funds, and they had almost $1 trillion under management by 2007 -- and likely more today.

At Harvard, Elena Kagan "proceeded to forge the law school's 'Islamic Finance Project." Its purpose, according to McCarthy, was "to promote Shariah compliance in the U.S. financial sector."

Indeed, when Harvard President Larry Summers -- now in the Obama administration -- accepted a $20 million donation for the creation of a program of studies of Islam's history and Shariah Law, Kagan raised no objection. The donation came from Saudi Prince Alwaleed bin Talal, a billionaire investor whose contribution of $10 million to the Twin Towers fund was refused by New York Mayor Rudy Giuliani because bin Talal had blamed the 9-11 attack on American foreign policy.

Harvard Law School now has three Saudi-funded institutions devoted to the study of Shariah.

Kagan, as a Supreme Court justice, will be required to rule frequently on possible applications of Shariah law in the United States. She has already noted that she welcomes "good ideas wherever they originate" and is open to applications of foreign law to the interpretation of U.S. statutes and common law.

In fact, a lawsuit seeking to ban Shariah Compliance Funds in banks that accepted TARP money (as violating the First Amendment - separation of church and state) is now making its way up to the Supreme Court. Kagan cannot be trusted to rule dispassionately on this case, nor can we rely on her to exclude Shariah law from American jurisprudence.

For this reason -- if for no other -- Senators should vote NO on her confirmation.