| LOS ANGELES
LOS ANGELES Over 38 million Americans tuned in for television coverage of Barack Obama accepting the Democratic nomination for U.S. president on Thursday in what is believed to be the most watched convention speech ever.
Obama's TV audience, reaching nearly a fourth of all U.S. households, was by far the largest of the four-day Democratic National Convention, surpassing the addresses by his running mate, U.S. Sen. Joe Biden of Delaware, and his onetime rival for the nomination, Sen. Hillary Clinton of New York.
It also easily eclipsed the acceptance speeches of either of Obama's two immediate Democratic predecessors or the 27.6 million viewers President George W. Bush drew on the fourth night of the Republican National Convention in 2004, when he was nominated for a second term.
Obama's historic address, by the first African American chosen to lead a major political party in the race for the White House, averaged 38.4 million U.S. viewers across all major networks, Nielsen Media Research reported on Friday.
That figure is the highest for any single night of any major party convention going back to 1996, the last election cycle for which Nielsen keeps night-by-night data.
The 1992 conventions as a whole garnered higher household ratings in prime time than this week's Democratic gathering in Denver, meaning a larger percentage of homes were tuned in to those earlier events. The same is true for most conventions held from 1960 to 1984.
But because today's household ratings translate into a larger number of individuals based on population growth, Nielsen analyst Anne Elliot said Obama's audience tally is probably the biggest for any televised convention speech in history.
By comparison, 24.4 million viewers saw the 2004 Democratic nominee, Massachusetts Sen. John Kerry, give his acceptance speech, and fewer still, 21.8 million, tuned in for the final night of the 2000 convention when then-Vice President Al Gore was nominated as the party's standard bearer.
The robust total for Obama, who delivered his speech in a football stadium packed with 84,000 cheering supporters, was yet another sign of the excitement generated by the Illinois senator's charisma and message of change.
The prime-time TV audience for all four days of the convention, averaging 30.2 million viewers, also easily topped the 24.4 million total for 2004 and 20.6 million from 2000.
Still, comparisons with previous election cycles are not precise matchups due to different Nielsen metrics.
In 2004, for example, Nielsen measured viewership across six networks -- the Big Three broadcasters ABC, CBS and NBC and cable news networks Fox News Channel, CNN and MSNBC -- whereas this year Nielsen added four smaller networks -- BET, TV One, Univision and Telemundo.
Moreover, Nielsen is now including time-shifted viewing by people watching later the same day through digital video recorders -- data not included in previous cycles.
The Republican National Convention kicks off in St. Paul, Minnesota, on Monday. Presumptive Republican nominee, Arizona Sen. John McCain, is hoping his bold pick of Alaska Gov. Sarah Palin as his vice presidential running mate, will raise the excitement level for his campaign.
(Editing by Bob Tourtellotte and Todd Eastham)