Over the past few weeks, troubling revelations have emerged about President Trump’s push to get Ukraine and China to investigate former vice president Joe Biden, a potential 2020 opponent. These discoveries have prompted Democrats to coalesce around an impeachment investigation. A few Republicans have also voiced concern, most prominently Sen. Mitt Romney (Utah), but most Republicans have either stayed silent or remained supportive of Trump.

Sen. Lindsey O. Graham (S.C.), a staunch Trump defender, has embodied the latter group. Graham has repeatedly demanded to know the identity of the whistleblower whose complaint precipitated the impeachment investigation. Graham’s career has gone through many chapters: impeachment manager arguing for the removal of President Bill Clinton; pragmatic conservative who was interested in cutting deals on issues including climate change, immigration reform and criminal justice reform; and now staunch backer of a man he once referred to as “race-baiting” and “xenophobic.”

Graham has cited several reasons for his transformation into a Trump loyalist, but he hasn’t hidden the role politics has played, telling the New York Times Magazine, “‘If you don’t want to get reelected, you’re in the wrong business.’” He only captured 56 percent of the vote against marginal challengers in his last primary, and recognizes that Trump is immensely popular among South Carolina Republicans, registering 72 percent approval among them in a recent Winthrop University poll. One tweet from the president could put Graham’s seat at risk.

While Graham’s transformation seems particularly mercurial given the harsh things he said about Trump during the 2016 presidential primary, and his close friendship with Sen. John McCain (Ariz.), whom Trump continues to attack more than a year after his death, Graham’s behavior fits within a long pattern in South Carolina politics. Politicians in South Carolina have repeatedly changed their positions in the name of political expediency, and if the case of the most famous of these switches is any indication, Graham may live in infamy for selling out his principles.

South Carolina has a sordid history of its senators switching their allegiances and beliefs to reflect the changing tides of public opinion. Arguably the most infamous example is John C. Calhoun. As a young politician, Calhoun served in the House of Representatives from 1811 to 1817. As a congressman, he was a voice of nationalism and an advocate for a more centralized federal government. Loyalty to these principles earned him the job of secretary of war in President James Monroe’s Cabinet during the purported “Era of Good Feelings” in which there was only one political party.

Calhoun’s political trajectory continued upward in the 1820s, landing him in the vice presidency under both John Quincy Adams and Andrew Jackson. Because the president and vice president didn’t run as a ticket during this time, Calhoun managed to serve both the staunchly nationalist Adams and Jackson, Adams’s principal rival. But by the time Jackson entered office, Calhoun’s devotion to nationalism had dissipated due to the political environment back home in South Carolina.

South Carolina was becoming a hotbed of states’ rights sentiment. The passage of the Tariff of 1828, referred to by some South Carolinians as the “Tariff of Abominations,” invigorated a belief in states’ rights. To maintain the possibility of a political career representing South Carolina, Calhoun closely followed the rising tide of states’ rights over nationalist sentiment in his home state and shifted his political allegiances accordingly.

While Jackson was not a champion of centralized government, he was a staunch believer in the Union and opposed the fervent states’ rights beliefs espoused by South Carolinians, including his own vice president.

This divergence and Jackson’s insistence on absolute personal loyalty from members of his administration made the relationship between Jackson and Calhoun increasingly fraught. The breaking point came in 1830, two years after Calhoun authored the “South Carolina Exposition and Protest,” which gave rise to a nullification movement among states’ rights zealots. The essay asserted that a state could nullify any federal law within its boundaries that it deemed harmful to its interests. Wealthy South Carolina planters feared the impact of tariffs benefiting Northern manufacturers at the expense of the raw material generated by their slave economy.

While Calhoun published the essay anonymously, his authorship was one of the worst-kept secrets of the time. At a dinner celebrating Thomas Jefferson’s birthday in 1830, the friction between Calhoun and Jackson came to a head when they presented dueling toasts. Jackson stated, “Our federal Union: It must be preserved!” to which Calhoun responded, “To the Union, next to our liberty, most dear.” This public divergence over states’ rights eventually led to Jackson regretting not hanging Calhoun as punishment for his role in the nullification crisis.

By the time of Jackson’s reelection campaign in 1832, Calhoun exemplified the dysfunction in the president’s Cabinet and administration. Determined to be rid of Calhoun, the president handpicked Martin Van Buren as his vice presidential candidate, ignoring criticism about his lack of transparency in removing Calhoun.

But that would not be the end of Calhoun’s political career. While he angered Jackson, Calhoun was accurately reflecting the sentiments back home in South Carolina, and the state legislature rewarded him with a Senate seat, which he held for a nonconsecutive 16 years until his death in 1850.

The once-staunch nationalist cozied up to the elite planter class that exerted sociopolitical control over South Carolina at the time. Despite being mythologized by white South Carolinians in the aftermath of the Civil War, Calhoun’s political cowardice in bowing to the extreme states’ rights views of the elites in his home state and re-creating himself as a leader of their interests had significant consequences beyond his lifetime. Calhoun’s essay encouraged the belief in secession and became a force beyond his control, with South Carolina eventually becoming the first state to secede from the Union in 1861, igniting the Civil War. This left Calhoun a hero in the South but deeply damaged his national reputation.

Among South Carolinians, Calhoun’s behavior was hardly unique. As he was shifting his politics, Sen. Robert Y. Hayne underwent the same transformation. More than a century later, Sen. Strom Thurmond switched parties in response to the passage of the Civil Rights Act of 1964. Perhaps fittingly, it is Graham who now holds Thurmond’s seat as he follows in the footsteps of these South Carolinians who prioritized power and politics over principles.

Graham’s actions, then, fit a pattern for senators from South Carolina, who have a history of brazenly replacing previous loyalties with the most polarizing sentiments espoused by their base. What makes these South Carolinians different from their peers in other states isn’t that their politics change over time, but rather that they’re audacious and unrepentant about it. In Calhoun’s case, that meant openly opposing his own administration’s policies while vice president. In Graham’s, it means doggedly defending Trump despite having been among his most vocal critics.

Undoubtedly, die-hard Trump supporters in South Carolina will hail Graham as a hero, but if Calhoun is any indication, history won’t remember Graham kindly, and the consequences of his actions for his career and, most importantly, for the health of American democracy, remain to be determined.