Donald Trump. (Photo by Ricky Carioti/The Washington Post)

During a campaign stop in Montana over Memorial Day weekend, Donald Trump promised he would expand the traditional presidential battleground into states long held by Democrats. “We’re going to play heavy, as an example, in California,” Trump said, before adding that his home state of New York was also on his list of targets.

Trump has broken lots and lots of long-held political rules in the course of his march to the Republican nomination. Given that record, there’s a tendency to assume that anything he says about what he will do in the future must be taken as fact. He said he was going to make a run at New York and California? Must be true!

Um, no.

Let’s count the reasons.

1.  New York and California are two of the most consistently Democratic states in the country.

The last time a Republican candidate for president won California was in 1988. That was four years more recent than the last time a Republican presidential candidate carried New York — and in that election Ronald Reagan won every state but one against Walter Mondale.

Here’s the Democratic candidate’s winning percentage in California for the past four presidential elections, going back to 2000: 60, 61, 54, 53. And here are those numbers for New York: 63, 63, 58, 60.  In other words, not close — and trending toward even less close. (More on the why of that trend below.)

And it’s not just at the presidential level where Democrats dominate. The last Republican to win a statewide federal election in New York was Alfonse D’Amato in 1992. In California, it was Pete Wilson — also in 1988. California’s Democratic senators were most recently reelected with 63 percent and 52 percent of the vote. In New York, the reelection numbers for the Democratic incumbents were 66 percent and 72 percent.

There are 39 Democrats and just 14 Republicans in the California U.S. House delegation. In New York, it’s 18 Democrats to nine Republicans.

2. New York and California are two of the most diverse states in the country.

Donald Trump — and Republicans more generally — have struggled to win over nonwhite voters in both this election and in recent past ones. (Mitt Romney got a meager 27 percent of the Hispanic vote nationally in 2012.) Any state that has a large nonwhite population is going to be very hard, therefore, for a Republican to win.

California is almost 40 percent Hispanic, according to the Census Bureau. More than one in three New Yorkers is not white.

In a statewide Siena College poll in New York released Tuesday, just 12 percent of African Americans and 15 percent of Latinos said they had a favorable impression of Trump. Among black voters, Trump was losing 84 percent to 9 percent to Hillary Clinton. Clinton’s margin among Hispanics was 53 points.

3. New York and California are two of the most expensive states in which to run ads in the country.

Both New York and California are huge — both in population and pure size. That makes reaching voters an incredibly costly proposition for any candidate.

California has 11 separate media markets, with Los Angeles being the most expensive.

New York has 10, with New York City being the most expensive.

If you want to advertise — and have anyone actually see the commercials — in either state, you need to make a multimillion-dollar-per-week investment in TV time. That price tag means no campaign can realistically afford to take a flier on making New York or California competitive. Trump could run ads in three actual swing states — Colorado, New Hampshire and Iowa, say — for the cost of a single week of TV in New York or California. Actually, for less.

Trump doesn’t need California or New York to get to 270 electoral votes and the White House. (Here are five maps that get Trump to the magic winning number.) That’s a good thing for Republicans. Because no matter what he says, he has no chance of winning either state.