ADVANCE FOR USE MONDAY, OCT. 22, 2012 AND THEREAFTER - FILE - In this Monday, Sept. 10, 2012 file photo, audience members bow their heads during an invocation during a campaign event fo

 

              ADVANCE FOR USE MONDAY, OCT. 22, 2012 AND THEREAFTER - FILE - In this Monday, Sept. 10, 2012 file photo, audience members bow their heads during an invocation during a campaign event fo
ADVANCE FOR USE MONDAY, OCT. 22, 2012 AND THEREAFTER - FILE - In this Monday, Sept. 10, 2012 file photo, audience members bow their heads during an invocation during a campaign event for Republican presidential candidate Mitt Romney in Mansfield, Ohio. In the sheer quantity of negative advertising and amount of dollars being spent, 2012 may mark the birth of an unprecedented era of negative campaigning, according to political scientists and campaign watchers. Contributing to the atmosphere is our extended campaign cycle of today, in which the barbs start flying long before the post-convention, fall campaign. (AP Photo/Charles Dharapak)