WASHINGTON (AP) — President Donald Trump is closing out his relationship with Congress with one more power jab, threatening to veto a hugely popular defense bill unless lawmakers clamp down on big tech companies he claims were biased against him during the election.

Trump is demanding that Congress repeal so-called Section 230, a part of the communications code that shields Twitter, Facebook and others from content liability. His complaint is a battle cry of conservatives — and some Democrats — who say the social media giants treat them unfairly.

But interjecting the complicated tech issue thr...