The story

Sen. Barack Obama is beginning his search for a running mate, but Sen. John McCain's campaign denies speculation that he's interviewing vice presidential candidates at his home this weekend.

A veteran Democratic activist said former Fannie Mae CEO Jim Johnson has accepted Obama's request to begin a screening and selection process for the No. 2 spot.

Johnson performed a similar role for Democratic presidential nominees Walter Mondale in 1984 and John Kerry in 2004. Read full article »

CNN's John King, Gloria Borger, Jessica Yellin, Ed Hornick and Paul Courson contributed to this report.

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