Sen. Dianne Feinstein (D-Calif.) officially declared her intention to run for reelection Monday, ending months of speculation about her future and probably avoiding what would have been an intense scramble of Golden State politics to succeed her. “I am running for reelection to the Senate. Lots more to do: ending gun violence, combating climate change, access to healthcare. I’m all in!” Feinstein tweeted. On Sunday, Feinstein hinted in a national television interview that she was likely to run again, telling NBC’s “Meet the Press” that she was close to a formal decision. Feinstein, 84, is California’s senior senator and the...