Nancy Pelosi has been in Washington D. C. for a long time and knows how national politics work. Democrats control the House, but the House alone isn't enough to get much done. Pelosi knows they need the White House and hopefully the Senate, too. She doesn't want the Democrats to overplay their hand in trying to oppose Trump and squander their opportunity to win back the White House and Senate next year. While Trump is spewing lies and hatred that Republicans scramble to defend, Pelosi want the Democrats to look like calm, level-headed adults whom Americans can trust to be control of government. Republicans understand this, too, which is why they are trying to portray Democrats as being controlled by radicalized extremists, embodied by "the Squad."