WASHINGTON (AP) — Rattled by accusations he was caving on his promised border wall, President Donald Trump instead bowed to a conservative backlash.

After signaling earlier in the week that he was backing off a government shutdown threat, Trump rapidly changed course on Thursday, informing House Republican leaders that he would not sign a short-term funding measure because it did not include money for a southern border wall. His second reversal in a matter of days — with time left to pivot yet again — came after conservative allies and pundits savaged him for waffling on a central campaign pro...