When reading The Economist, I came across this sentence below in bold. According to grammar, we know a sentence must end up with a full stop, instead of a comma. But in this case, "Mr Trump is the president" and "47% of Americans trust him more than they trust the media" both are sentences, why?
IT WAS almost as if Donald Trump was taunting his Republican colleagues. After tweeting an explosive and wholly unsubstantiated claim against Barack Obama on March 4th—“How low has President Obama gone to tapp [sic] my phones…Bad (or sick) guy!”— the president said it was up to Congress to investigate the matter. “Neither the White House nor the president will comment further,” primly declared his spokesman, Sean Spicer, “until such oversight is conducted.”
Some sort of follow-up is necessary. Mr Trump is the president, 47% of Americans trust him more than they trust the media (according to a Quinnipiac poll), and his charge against Mr Obama was grave. If it were shown that his administration illegally snooped on Mr Trump, Mr Obama’s legacy would be disgraced.