President Biden held a high-stakes news conference Thursday in which he was forceful and defiant, vowing to pursue re-election and finish the job he started, but he also made some flubs as he tried to slow a stream of Democratic defections that risked turning into a mutiny. Democrats have continued to break with their 81-year-old standard-bearer following a calamitous debate and public appearances that haven’t reassured colleagues about his fitness for the campaign trail or a second term.
