That strategy is beginning to take shape, with groups that support Mrs. Clinton preparing to script and test ads that would portray Mr. Trump as a misogynist and an enemy to the working class whose brash temper would put the nation and the world in grave danger. To fight Mr. Trump’s ability to sway the news cycle, Mr. Clinton would not hold back on the stump, and President Obama has told allies he would gleefully portray Mr. Trump as incapable of handling the duties of the Oval Office.
“He’s formidable, he understands voters’ anxieties, and he will be ruthless against Hillary Clinton,” said Gov. Dannel P. Malloy of Connecticut. “I’ve gone from denial — ‘I can’t believe anyone would listen to this guy’ — to admiration, in the sense that he’s figured out how to capture everyone’s angst, to real worry.”
...
Now, Mr. Mook and his colleagues regard Mr. Trump as a wily, determined and indefatigable opponent who seems to be speaking to broad economic anxieties among Americans and to the widely held belief that traditional politicians are incapable of addressing those problems. ...privately, other Democrats are poring over polling data to understand the roots of Mr. Trump’s populist appeal and building up troves of opposition research on his business career.
“The case against Trump will be prosecuted on two levels,” said Geoff Garin, a Democratic pollster and Mrs. Clinton’s chief strategist in 2008. “The first is temperament,” and whether he is suited to be commander in chief, Mr. Garin said, echoing conversations that have dominated Democratic circles recently. The second “will be based on whether he can really be relied on as a champion for anyone but himself.”