It just kills the narcissist in the White House that he cannot come up to the numbers (or popularity) of President Obama. Although he denies it, Trump had a much smaller crowd attending his inauguration than Obama did -- and that extended to the TV audience watching those inaugurations.
Now we have the numbers for Trump's first speech to a joint session of Congress -- and once again he finished behind President Obama. Trump had a 27.8 overnight share of the TV audience, while Obama had a 33.4 share. That translates into 48 million viewers for Trump and 52.4 million for Obama.
It's just one more hit to Trump's massive ego.
