Washington, May 27 (RHC)-- U.S. Democratic presidential front-runner Hillary Clinton has defended using a private e-mail server while serving as secretary of state, saying the e-mail controversy will not affect her White House bid.

In an interview with CNN on Thursday, Clinton insisted her actions were no different than that of her predecessors, and claimed that she would not allow the issue to dog her election campaign.

Republicans have long speculated that the federal investigation into Clinton's use of a private e-mail server while she was US secretary of state could result in criminal charges against her.  More than 2,000 e-mails sent and received by Clinton while working as the top U.S. diplomat between 2009 and 2013 include classified information, which the government bans from being handled outside secure, government-controlled channels.

Earlier this month, a U.S. federal judge in Washington said he might order Clinton to testify under oath about whether she used a private e-mail server.  U.S. District Court Judge Emmet Sullivan signed an order granting a request from the conservative watchdog group Judicial Watch to question six current and former U.S. State Department staffers about the creation and purpose of the private e-mail server.