Astonishing many political pundits who predicted that the first John McCain-Barack Obama would attract a record audience for a presidential debate, preliminary Nielsen figures indicated over the weekend that the debate actually drew 12-percent fewer viewers than the 2004 debate between George Bush and Al Gore. Figures were based on electronic ratings conducted in 55 of the largest markets. More detailed ratings are expected to be released later today (Monday) but are unlikely to alter the original figures significantly, analysts said. The four major broadcast networks together earned a 34.7 rating, representing about 29.53 million viewers. (Ratings for the cable news networks were not immediately available.) By contrast, the 1980 debate between Ronald Reagan and Jimmy Carter captured a 58.9 rating, representing 80.6 million viewers. ABC drew the biggest audience for the debate, averaging 10.20 million viewers. NBC came in second with 7.75 million viewers. CBS followed closely with 7.44 million, while Fox trailed with 4.14 million.