hillary_clinton_sad.jpgSen. Hillary Rodham Clinton will drop out of the race for the presidential nomination by the end of the week, CNN and ABC are reporting.

Sen. Barack Obama, the presumptive Democratic presidential nominee, began to search for a running mate Wednesday as Democratic leaders indicated to Clinton that her bid to become the nation’s first female president was over.

Behind the scenes, Clinton’s supporters made a case for her as Obama's vice presidential running mate.

Obama picked former President John F. Kennedy's daughter, Caroline, to help him choose a vice president.

Yet Clinton refused to concede the race, even after Tuesday's primaries and a stream of superdelegates endorsed Obama, allowing him to seal the nomination.

Even so, there were many signs that she was shutting down her campaign. She began saying goodbye to campaign staff members, and a number were told not to come to work after Friday, according to The Associated Press. Last paychecks were expected to go out June 15.

Obama showed no impatience, merely smiling and accepting congratulations from colleagues in both parties as he returned to the Capitol for a Senate vote. But other Democrats urged Clinton to get out of the way, the AP reported.

"I don't see why we don't get on with it and endorse" Obama, Rep. Charles Rangel, a congressman from Clinton's home state of New York, told the AP, adding that it was only a matter of time before he and other Clinton supporters formally back Obama.