Woe to the politician who, while campaigning in a particular state, pronounces the state’s name differently from the local denizens.

The latest casualty of this phonetic parochialism is Matt Rosendale, currently the frontrunner among Montana Republicans seeking to oppose the incumbent Jon Tester in this year’s U.S. Senate race. Democrats have already set their sights on Rosendale by issuing an online ad that plays up the fact that he moved to Montana from Maryland some 15 years ago. His accent, the ad suggests, is proof that Rosendale—dubbed “Maryland Matt” by the Democrats—is an interloper who doesn’t share “Montana values.”

While Rosendale’s accent is indeed distinctly non-Montanan, the ad focuses on his pronunciation of one word in particular: “Montana.” As befits someone of Rosendale’s background from Maryland’s Eastern Shore, there’s something peculiar about how he pronounces the vowel in the second syllable of “Montana.” (More on that in a bit.)

Rosendale is hardly the first politician to be ridiculed for his pronunciation of a state name. In October 2016, Donald Trump tried—and failed—to pronounce “Nevada” the Nevadan way at a rally in Reno. Locals prefer pronouncing the second syllable like “add” and bristle at outsiders saying it like “odd.” Trump must have been informed of this before the rally but still managed to get it exactly backwards.

“Heroin overdoses are surging and meth overdoses in Nevada,” Trump said, making a point to pronounce it as “Ne-VAH-da.” He continued, “And you know what I said? I said when I came out here, I said nobody says it the other way, has to be Ne-VAH-da. And if you don’t say it correctly, and it didn’t happen to me, but it happened to a friend of mine, he was killed.”

As University of Pennsylvania linguist Mark Liberman observed on Language Log at the time, “it seems to tell us something about Donald Trump’s style that he tries to bond with Nevadans over right vs. wrong ways to pronounce the name of their state—and gets it wrong.”

Julia Louis-Dreyfus, star of the HBO show Veep, couldn’t help noticing how life imitated art, since Veep featured a running joke about politicians’ inability to pronounce “Nevada” the Nevadan way. On Twitter, she shared a video intercutting Trump’s misstep with scenes from Veep’s fifth-season episode appropriately entitled “Nev-AD-a.”

If Trump had been more attentive to recent political history, he might have known that in 2004 both George W. Bush and John Kerry were criticized for using the “Ne-VAH-da” pronunciation on the campaign trail. As the Las Vegas Review-Journal reported at the time, Bush and Kerry both eventually corrected themselves. When Bush made a point of using the local “add” pronunciation in a speech in Reno, he joked, “I bet you didn’t think I would get that right!”

It’s tricky for politicians, especially on the national level, to “get it right” when it comes to state names, since very often variant pronunciations become shibboleths, delineating insiders from outsiders. This is especially the case for state names derived from Native American, Spanish, or French roots, which can be localized in idiosyncratic ways.

An early example of a state making an issue of how to pronounce its name is “Arkansas”—which in the 19th century was frequently said as “Ar-KAN-sas” by those from outside of the state. This became such a point of contention that in 1881 the Arkansas General Assembly unanimously adopted a resolution declaring that the proper pronunciation is “AR-kan-saw.”

Since then, Arkansans have succeeded in propagating their preferred pronunciation. Likewise, Illinoisans insisted that it’s “Ill-i-NOY,” not “Ill-i-NOISE.” In some cases, local variants have simply faded away, such as the pronunciation of “Iowa” as “I-o-way.” But other times, as with “Nevada,” a variant remains favored within the state’s borders but gets ignored by outsiders. Just ask residents of Colorado (they tend to use the “add” pronunciation like “Nevada”) or Oregon (they keep the final syllable unstressed instead of saying “gone”).

“Missouri” is another prominent example of a pronunciation split, with many Missourians calling their state “Mizzoura.” But there is a regional complication: in a poll by Midwest Motorist conducted in 1976, “Mizzoura” was favored in the western part of the state, while those in the east were more likely to pronounce the final syllable as “-ee.” A decade later, Missouri-born humorist Calvin Trillin argued, semi-seriously, that Kit Bond’s defeat of Harriet Woods in the state’s 1986 U.S. Senate race hinged on Bond’s use of the more authentic “Mizzoura” pronunciation.

Could Rosendale encounter the same problem running for Senate in Montana? His situation is a bit different, because “Montana” does not actually have the same insider-outsider split as, say, “Nevada” or “Colorado,” even though all three state names come from Spanish roots. Most Americans, whether from Montana or elsewhere, would pronounce “Montana” to rhyme with “banana,” using what linguists call the TRAP vowel in the second syllable, rather than like “nirvana,” which uses the LOT vowel. (Apologies to British speakers and others who rhyme “banana” with “nirvana.”)

So what’s going on with Rosendale’s “Montana”? As a native of the eastern shore of Maryland, he has a dialectal feature known as the “short-a split,” common to the Mid-Atlantic region encompassing Philadelphia and Baltimore. For speakers of this dialect, the TRAP vowel becomes “tense” in some words and “lax” in others. You can hear this more clearly by listening to a clip from Rosendale’s closing remarks in a recent Republican primary debate.

In words like “bad,” Rosendale makes the TRAP vowel tense, something like “bee-ud.” But his vowel in the second syllable of “Montana” is very lax, which can sound more like the LOT vowel to those who lack a “short-a split.” Christine Mallinson, a sociolinguist at University of Maryland, Baltimore County, tells me that this vowel feature is typical of white, working-class speech in the region where Rosendale grew up.

As you can hear from the clip of Rosendale speaking, he has plenty of other Mid-Atlantic dialect features, such as an “o” diphthong that is “fronted,” or pronounced closer to the front of the mouth. (ESPN’s Scott Van Pelt can reduce fellow Marylander Tim Kurkjian to tears by pronouncing players’ names with a fronted “o” in an exaggerated Baltimore accent.) But despite all that, Montana Democrats are making the case that Rosendale is an East Coast carpetbagger based solely on his pronunciation of “Montana.” As an expression of “in-group” identity in American politics, how you say a state’s name can be powerfully symbolic.