Trump goes after Rev. Sharpton after slamming Rep. Cummings; Attacks on Cummings come one week after Trump lashed out at 4 Democratic women of color; Mulvaney: Trump's comments on Cummings are not about race; GOP Meadows yet to defend "best friend" Cummings after attacks; Michigan gov. talks 2020 Dems & beating Trump in her state; Michigan Dem. Party Black Caucus endorses Kamala Harris; Harris' "Medicare for all" plan keeps private insurance; Sanders reacts to Harris' "Medicare for all" proposal; Sanders: Harris' plan is "not Medicare-for-all"; 3 killed, 12 wounded in shooting at California festival; Police: Festival shooter used assault-style weapon; Gunman posted about white supremacist book before attack; Children ages 6 & 13 among three killed in festival shooting; 2020 Dems agree to fight climate crisis, but not on a plan; Half of 2020 field has released comprehensive climate plan via Knit