Sixty-one percent of all U.S. households watched at least one of the two 2008 election debates aired so far, according to a new analysis released Monday by Nielsen.

On average, 41% of all homes watched the V.P. debate last Thursday — up one-third from the first presidential debate the previous Friday night, which reached an average of 31% of all households.

Of all households, 39% watched neither debate, while 30.3% tuned in to both.  11.2% of all homes tuned in to the presidential debate only, and 19.5% tuned in to just the V.P. debate. 

Both debates drew audiences made up mostly of white viewers with higher levels of income ($100,000+) and education (4+ years of college).

Older viewers (age 55+) made up the largest portion of the TV audiences for both debates (42% – 46%).  However, the Biden-Palin V.P. debate (median age: 52) drew a slightly larger portion of younger viewers than the first Obama-McCain debate (median age: 54).

Homes headed by African Americans made up a larger portion of the presidential debate audience (14.0%) than the V.P. debate audience (12.3%).  African American homes normally account for 12.2% of all U.S. TV households.

Overall, Hispanic viewers were less likely to watch the debates.  Hispanic households, which account for 11.1%  of all TV households in the U.S., made up just 6.3% to 6.5% of the combined audience for the two debates. 

A closer look at the minute-by-minute ratings for both debates reveals few peaks or drop-offs in household viewing, which remained steady throughout both the telecasts.

Read the full report — and stay tuned during the presidential debates for more Nielsen TV audience analyses.