Last week, Donald Trump stood in front of a sea of "Trump digs coal" signs at a rally in Abingdon, Va., a town of 8,000 people nestled in between Tennessee, West Virginia and Kentucky. Trump pledged to the crowd that, as president, he would be the region's champion, vowing to keep coal miners in the area employed.

Earlier this month, he was in a different part of the state, at Trump National Golf Club in Northern Virginia. There, he was interviewed by The Washington Post's Philip Rucker. The two discussed Sen. Tim Kaine's speech after the Virginia Democrat was named Hillary Clinton's vice presidential running mate.

TRUMP: Yeah, I thought he was terrible. I thought his speech was terrible. Although he’s not popular here. You know, this is Loudoun County. Loudoun County’s a big deal.
RUCKER: Whoever wins Loudoun wins the election.
TRUMP: Is that what you think?
RUCKER: It’s one of the swing counties, yeah.
TRUMP: Hey, George! Come here. He just said whoever wins Loudoun wins the election. This is Loudoun.
GEORGE GIGICOS (Trump campaign aide): We’re in Loudoun County now.
TRUMP: You got 800 acres in Loudoun.
RUCKER: Loudoun, Fairfax —
TRUMP: What about Fairfax? Same thing?

Abingdon is in Washington County, where about 55,000 people live. Loudoun County is nearly seven times as large — meaning it has nearly seven times as many voters. Adjacent Fairfax County has over 1.1 million residents.

Trump had held rallies in Loudoun; he had one in Ashburn at the time of the Rucker interview. But the way in which he's prioritizing Virginia — and the way the state views his candidacy — makes clear why the Republican presidential nominee is trailing Clinton nationally.

Polling Manager Scott Clement conducted The Post's most recent poll and answered questions about the results and methodology.

The new Washington Post poll in Virginia puts Clinton up 14 points in the state, or eight points among likely voters (who tend to skew more Republican).

If we break that down by region, you can see Trump's problem, particularly when compared to how Mitt Romney fared in 2012, when he lost the state by about four points. In every region besides the central/western part of the state, Clinton leads Trump by more than President Obama led Romney. In the central/west region, which includes Abingdon, Trump outperforms Romney by a hair.

This is the pattern we have seen after the conventions: Trump is solidifying a core group of voters but not expanding his support anywhere else. A slight uptick in a less-populated part of the state can't make up for huge swings in places with a lot of voters. The margin in the Washington suburbs in the poll, for example, dwarfs how Fairfax has voted in past elections as it has shifted to the Democrats. Loudoun, an exurb county, has not moved as far to the left as Fairfax. But in this election, our poll has the region near Loudoun's recent peak in preferring the Democrat.

Obama won the D.C. suburbs by 26 points. Clinton is leading by 45 points. That's doom for Trump. It's in part a function of the ongoing demographic shifts in the area, but it certainly doesn't help that two weeks ago Trump didn't understand the importance of the region.

Trump is leading with demographic groups that Romney won in 2012, including white men and, in particular, white men without college degrees. But he's actually underperforming with those voters, relative to 2012 exit polling. Clinton is outperforming Obama with white voters — and independents, where she leads.

The recurring theme to Trump's poor poll performance is that he is also underperforming with Republicans. Democrats are supporting Clinton in Virginia at about the rates that exit polls suggested in 2012. Trump is doing 18 points worse than Romney. Among conservative Republicans and Republican-leaning independents, Trump gets nearly 9 in 10 votes. Among moderates, he gets under two-thirds and Clinton gets a fifth.

So Trump spends time in a lightly populated part of the state where there aren't many more votes to win; he does slightly better there than Romney did in 2012. Among the more populous (and more diverse) parts of the state, Trump is getting demolished, thanks in part to antipathy from Republican voters in those areas. Trump can't seem to find more votes, and it's not clear what his strategy is to do so.

Other polls show that this trend is not confined to the state of Virginia.

What Donald Trump is doing on the campaign trail

MANCHESTER, NH - NOVEMBER 7: Republican presidential candidate Donald Trump speaks during a campaign event at SNHU Arena in Manchester, NH on Monday November 07, 2016. (Jabin Botsford/The Washington Post)