In response to Conway, 538's Nate Silver raised an interesting point.
And that's also true. Trump always likes to say that he received more votes than any previous Republican nominee, which is accurate, but it's also accurate that a record was set for most votes cast for candidates other than the eventual nominee.
Using data from U.S. Election Atlas and the Congressional Quarterly Guide to Elections, we can plot contests since 1972 (after the reforms that followed the 1968 process) and demonstrate that only five times have major-party nominees earned less than 50 percent of the vote in both the primary and the general — and only once, this year, has that person ended up winning the presidency.
Jimmy Carter and Bill Clinton were close. In 1976, Carter barely topped 50 percent in the general, and in 1992 Clinton barely edged past 50 percent in the primary. In every other contest, the winner got more than half of the support from his or her own party, or the nation as a whole.
Update: Since someone on Twitter asked, the other four people to get under 50 percent in each contest were John McCain (2008), Michael Dukakis (1988), Walter Mondale (1984) and George McGovern (1972).
Interestingly, both of the last two losing candidates got more of the vote in the general election than did Trump. Trump earned about 46.3 percent of the vote (though ballots are still being counted) to Mitt Romney's 47.2. (Romney also did better than Trump in nearly half the states.) Hillary Clinton, of course, beat Trump in the popular vote this year, which is where this whole thing started.
So Conway's right: Winning the popular vote in the presidential contest is like getting the most hits in a World Series Game 7 that you lose by a run in the ninth. Good job, I guess, but who cares. It does, however, reinforce the idea that any claim to a Trump mandate, much less a landslide should be taken with a grain of salt.
More Republicans voted for someone besides Trump than voted for him in the primary, but he won. More Americans voted for Trump's opponent in the general, but he won.
Had we been saying this about Clinton, I think it's safe to guess the word Trump would have used to describe her victory: Rigged.