Can Donald Trump Win? These Battleground Regions Will Decide

With Donald J. Trump pulling even or ahead of Hillary Clinton in a series of recent national polls, the once unthinkable has become at least plausible. But if he is to be elected the 45th president, he must compete on a political map that, for now, looks forbidding. In the Republican primaries, he proved a master of nationalizing the political debate, appealing to voters across regional lines with jeremiads about immigration and crime that captivated an almost uniformly white primary electorate. At the outset of the general election, Mr. Trump has dominated the day-to-day political combat on national television and social media. In the general election, however, his fate will be determined not by his Twitter followers or a relatively homogeneous Republican electorate, but by a set of interlocking and increasingly diverse regions, home to some 90 million Americans, that hold many of the 270 electoral votes he needs to win.