By Lisa Richwine
   Jan 24 (Reuters) - The U.S. television audience for Democrats' arguments that President Donald Trump should be impeached declined on Thursday to roughly 7.8 million viewers during live daytime coverage, according to data from the Nielsen ratings agency.
   The viewership was a 29% drop from Tuesday afternoon when about 11 million watched lawmakers spar over evidence and witnesses for the third presidential impeachment trial in U.S. history.
   TV viewership fell to 8.9 million on Wednesday as Democrats began making their case to the U.S. Senate and at the same time reach voters ahead of the November presidential election.
   Nielsen's TV ratings do not include people who watched live coverage via online streaming or followed it via social media.
   Democrats argued that Republican Trump abused his power and obstructed justice for pressuring Ukraine to investigate former Vice President Joe Biden, one of his potential Democratic opponents in November, and impeding the inquiry into the matter. They were due to wrap up their case on Friday .
   The Republican president denies any wrongdoing.
   The impeachment trial is unlikely to end with a vote that removes Trump from office, as Republicans who control the Senate have voiced support for the president.
   Six broadcast and cable networks have aired live coverage of the impeachment trial during the day. They are Walt Disney Co's  ABC, AT&T Inc's CNN, ViacomCBS's CBS, Comcast Corp's NBC and MSNBC, and Fox Corp's  Fox News. Cable channels are broadcasting the trial live in the evenings.

(Reporting by Lisa Richwine; Editing by Andy Sullivan and Grant
McCool)
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