15 years after Sept. 11: How the unity we forged broke apart 

NEW YORK (AP) - For a time, it felt like the attack that shattered America had also brought it together.

After Sept. 11, signs of newfound unity seemed to well up everywhere, from the homes where American flags appeared virtually overnight to the Capitol steps where lawmakers pushed aside party lines to sing "God Bless America" together.

That cohesion feels vanishingly distant as the 15th annivers...