President Joe Biden accused Donald Trump and his supporters of holding a “dagger at the throat of democracy” in a forceful speech Thursday marking the anniversary of the deadly attack on the U.S. Capitol. He warned that though it didn’t succeed, the insurrection remains a serious threat to America’s system of government. Biden’s criticism was blistering of the defeated president whom he blamed for the assault that has fundamentally changed Congress and the nation, and raised global concerns about the future of American democracy. “For the first time in our history, a president not just lost an election, he tried...