One of the most pervasive myths in American politics is that a “Big Blue Wall" will protect Democratic presidential nominees, perhaps even those who lose the popular vote. In truth, this electoral Blue Wall is more like a collection of disconnected forts—some imposing, some not—and the loss of any one of them would likely doom the Democratic nominee.

The Blue Wall—states where the Democrats have won every presidential race since 1992—includes the entire Northeast except for New Hampshire, the Midwestern Great Lakes states aside from Ohio and Indiana, the three Pacific Coast states, and Hawaii. Even holding the wall is no guarantee of victory. John Kerry won the entire Blue Wall in 2004, plus New Hampshire, yet still lost to George W. Bush by 35 electoral votes. Al Gore won the entire Blue Wall in 2000—back when it was worth 13 more electoral votes—plus Iowa and New Mexico, yet still lost to Bush by 5 electoral votes. For the Democrats, holding the Blue Wall is necessary but not sufficient.

It is often claimed that Donald Trump has several must-win states, and this is true (although the states listed are often wrong). In addition to the 23 states that Mitt Romney won by at least 7 percentage points, which Trump isn't going to lose, Trump has 3 must-win states: Ohio, Florida, and North Carolina. (Polling finds that Trump narrowly overtook Clinton in mid-September in all three.) If Hillary Clinton wins any of those states, it'll be a knockout blow.



But in addition to the 15 states where President Obama beat Romney by at least 10 points, which Clinton isn't going to lose, Clinton has 5 must-win states: Pennsylvania, Michigan, Wisconsin, Minnesota, and Virginia. (Polling finds her ahead in all five.) The first four are part of the Blue Wall; the Old Dominion is not. If Trump wins any of those states, he'll be headed to the White House.

So there are eight potential knockout states in this election, and five of them are being defended by Hillary Clinton.

If both candidates win their respective must-win states (and split the two competitive congressional districts in Nebraska and Maine), that will bring the electoral-vote tally to 260 for Clinton and 253 for Trump, with Colorado, Nevada, Iowa, and New Hampshire (25 combined electoral votes) still in play. Clinton's task would then be to win any two of the four remaining states; Trump's task would be to win any three. If Clinton wins Colorado and Trump wins the other three, the candidates would be tied at 269, with the election moving to the House of Representatives.

The Five Paths

Clinton's path to 270 is relatively simple: (a) steal Ohio, Florida, or North Carolina; or (b) win her five must-win states and prevent Trump from getting 16 more electoral votes from among the 25 remaining on the board. (If Clinton wins right-leaning Ohio, Florida, or North Carolina, there's no way she'll fail to win the requisite number of left-leaning states.) Trump's task is to win his 3 must-win states (plus the 23 states that are givens) and then follow any one of five different paths to winning the remaining 17 electoral votes he'd need to achieve victory.

The Virginia Path: Many commentators quickly wrote Virginia off for Trump. This reflected unfavorable early polling as well as Republicans' demoralization over Virginia's having moved left in recent years. But Trump's poll numbers have looked much better there of late, and Republicans have generally overreacted to the Old Dominion's leftward shift. Moreover, the early polling in Virginia was surely affected by Clinton's having had ads on the air there while Trump didn't. By late August, Clinton had spent more than $5 million on ads in Virginia, according to Associated Press tallies, to Trump's $0.

Of all the left-leaning states, Virginia is the most centrist. It was just 0.02 points to the left of the national average in the 2012 presidential election, and it slid only 1 point further leftward between 2008 and 2012. It's also where Trump's efforts to reach out to black voters—which he's done more than any other GOP nominee in memory—could pay off. Roughly 20 percent of Virginia's population is black, compared with 13 percent nationally.

If Trump wins Virginia, then he almost surely isn't going to lose Florida or North Carolina (both of which are noticeably to Virginia's right), almost surely isn't going to lose populist Iowa (where polls suggest he is faring about 5 points better than he is nationally), and isn't likely to lose Ohio (which is a bit to the right of Virginia and shows him polling better). The combination of these states would give him 272 electoral votes.

During the week of September 4-10, Trump smartly spent $2.2 million in Virginia—double what he spent in any other state—according to AP. Clinton, meanwhile, spent $0, choosing instead to waste money in Arizona and Georgia, where she isn't going to win and doesn't need to win.

The Midwestern Path: Normally, Michigan would be too heavy of a lift for a Republican candidate in a close race. On average, across the past five presidential contests, the state has been 6 points to the left of the nation. But Trump's working-class message and manner seem tailor-made for Michigan, and it's possible he could turn the state, as Obama did Virginia in 2008. Alternatively, he could pull off an upset in Wisconsin or Minnesota, states that are generally to the right of Michigan.

Clinton hasn't run any ads in Michigan (or Wisconsin or Minnesota), while Trump has run a few there of late. Trump announced his economic plan in Detroit and delivered one of his campaign's best lines just down the road: "[I]t used to be, cars were made in Flint and you couldn't drink the water in Mexico. Now the cars are made in Mexico and you can't drink the water in Flint."

If Trump wins his must-win states, plus Michigan and Iowa, he would have 275 electoral votes.

The Colorado Path: Between June 12 and July 16, Clinton spent about $4 million unopposed in Colorado, while building up a double-digit lead there in the polls. But the Trump campaign didn't write off the state. It spent $1.1 million there from September 4 to 10, according to AP, to Clinton's $47,000. The only Colorado poll taken in September (released on September 15) found Trump up 4 points.

Colorado is a somewhat volatile state whose voters may not be inclined to back the third Obama term for which Clinton is effectively running. The state was slightly left of the nation in 2008 and 2012, but by less than 2 points each time. In each of the past four elections, it has supported the winner by more than he has won by nationwide. Additionally, Colorad-ans haven't seemed too impressed with the Clintons in the past. After more or less mirroring the nation and backing Bill Clinton by 4.3 points in 1992 (he won by 5.6 points nationally), Colorado swung far to the right of the nation in 1996, supporting Bob Dole by 1.4 points in a race that Clinton won by 8.5 points nationwide.

If Trump were to hold his must-win states and win Iowa, he could win the presidency by pairing a win in Colorado with one in either Nevada or New Hampshire. He could also get to 269—and the House—by winning his must-win states, Iowa, Colorado, and Maine's 2nd Congressional District (worth one electoral vote), where polling finds him up 5 points (per Real Clear Politics).

The New Hampshire Path: While Clinton was squandering money in Arizona and Georgia, Trump sensibly outspent her $576,000 to $350,000 in New Hampshire during the week of September 4-10. New Hampshire is famously populist and independent, is predominantly white, and has an older population (which usually favors Trump). Trump did extremely well there in the GOP primary. While the Real Clear Politics average finds Clinton up by roughly 5 points in the Granite State, she has outspent Trump there to date by a tally of $5.2 million to $598,000. During the week of September 11, after Clinton was propped up, picked up, and folded into her van, she spent more on ads in New Hampshire than in any other week so far, while Trump didn't press his advantage.

If Trump holds his must-win states, a win in New Hampshire, paired with wins in Iowa, Nevada, and Maine CD-2 (or in Iowa and Colorado) would get him to 270 (or 272, in the Colorado scenario) without having to win a single left-leaning state with double-digit electoral votes. This inviting path could be complicated, however, by national Republicans' apparent and peculiar reluctance to fund Senator Kelly Ayotte's reelection bid. RCP, which reported this reticence, shows Ayotte with a narrow 2-point lead, despite her having been outspent two-to-one. New Hampshire is a small state, but it's not impossible that it could end up deciding which party controls both the White House and the Senate.

The Pennsylvania Path: The most oft-discussed path to a Trump win is through Pennsylvania. Paired with victories in his must-win states, a triumph in Pennsylvania would give Trump 273 electoral votes.

Trump's platform and personality seem well-suited to the Keystone State, but it's hard to say how things are shaping up there. On the one hand, Clinton is polling strongly in the state, faring about 5 points better than she is nationally. On the other hand, AP reports she has outspent Trump there by about five-to-one. It could be that Pennsylvania will continue its streak, now dating back 16 presidential elections (to 1952), of going to the Republicans only when the Republican wins by enough nationally that he doesn't need it.

Trump can win without Pennsylvania, though. Indeed, he might have a better shot at victory via the Virginia, Michigan, Colorado, and New Hampshire paths. His best strategy at this point would seem to be to make Clinton defend all five paths, which is what his campaign appears to have in mind. That might put a degree of strain on the Blue Wall that the fabled fortification can't withstand.

Jeffrey H. Anderson is a Hudson Institute senior fellow.