Never one to hold back, Senator Harry Reid of Nevada, the Democratic leader and bane of the Koch brothers and Mitt Romney, made clear on Thursday that he intended to spend much of the rest of the year savaging Donald J. Trump. In a conference call with reporters from his home in Las Vegas, Mr. Reid lit into Mr. Trump, calling him anti-woman, anti-Hispanic, anti-Muslim, anti-immigrant, anti-President Obama and anti-working people, to name a few. “It is a sad day for Republicans when they decide to bow to Trump,” said Mr. Reid, who is not running for re-election, potentially freeing...