I'm going to go ahead and put a warning for racism and language here. We're talking about Lincoln, so if talking about racism, racist violence, slavery, or the word nigger upsets your sensibilities then you should probably skip this. I'm not going to be gratuitous but there's no real way to avoid those things.

Yes, he was.

Abraham Lincoln was from a working class to perhaps middle class family. His father was a tradesman and early on Lincoln worked at a corner store, which are still roughly of the same social status now as back then. This isn't to say he came from absolute poverty or destitution: his family would be closer to lower middle class, say. But they were certainly not aristocrats even in their own locality, let alone on the national scale. Nor was he raised in the manners, hobbies, or religion of the American elites. Lincoln and his friends got into fights in his youth. When he served in the militia, he didn't make officer. He became a lawyer by reading a law, a pathway that has since been banned or regulated out of existence. Instead, more elite and professional routes are the only ways to get into law. He was, on the whole, a middle class type at best.

Of course, he had his own talents. Not the least of which was a keen political instinct. But in pure class terms he was not someone who could be expected to rise to the highest office. It was somewhat unusual that he even rose to prominent state office, something enabled by the rural and farmer based society he lived in. In the East or South he would have likely stood much less of a chance. And this was key to his entire political career. Lincoln generally played up his roots. This in turn defined him to many people, either for good or ill.

The second scene in Lincoln has some white country soldiers come up to Lincoln stammering about how great his oratory is and how inspiring he is. That's fairly accurate. (Less accurate is their referencing the Gettysburg Address, which was not famous at the time. It's possible just not likely.) Lincoln was a noted orator who spent a lot of time on rural circuits. He was "one of them" to rural, low church religious white farmers. Those were the people who put him into office early in his career and remained a key constituency long after.

They were the solid base of support that propelled him to the Republican nomination. At the 1860 Convention, Lincoln didn't win any voting rounds until the last one. A candidate had to win a majority of present delegates. Lincoln came in second in the first round, behind Seward. Lincoln's supporters were the representatives of rural voters in the Midwest, Appalachia, and northern New England (Maine and New Hampshire). There were three more votes after that and this core base of support not only stayed loyal to him but expanded to include places like Kentucky, Kansas, and Connecticut. It was only in the last vote that a few urban states turned to Lincoln. And even then, most of them didn't. DC's Republicans, for example, voted for Seward.

Seward was just as anti-slavery as Lincoln. But he was better educated from a much more aristocratic background. So were most of Lincoln's opponents for the nomination. In fact one of them, Chase, was a lawyer like Lincoln but from a much more respectable background. Lincoln would appoint him to the Supreme Court to both get an avid anti-slavery advocate on the court and to neutralize him politically. Out of all the serious candidates at the 1860 Convention, Lincoln was undoubtedly the least wealthy and educated and generally aristocratic. This was true in the general as well. This was an advantage electorally but not socially.

The cities, meanwhile, were almost all Democratic. You will note the cities are where most playhouses and high art flourish. Though certainly not all art. For example, Lincoln's first stage play was in DC but not his first play. As you'll note, living in a city is definitionally the opposite of a bumpkin. There's a point to be made about prejudice here but that's for another time.

This Democratic affiliation meant urban politicians and the urban elites had, for decades, been in an alliance with slaveholders. For some it was an alliance of convenience and an increasingly uncomfortable one. A few broke broke ranks in 1856 and 1860 and voted Republican over the issue of slavery, most notably Boston. But most Democrats, and by extension most cities' politicians, were at least moderately pro-slavery. The difference between the Northern Democrats and Southern Democrats were how pro-slavery they were and their acceptance of radical action to preserve slavery. But neither was Abolitionist. New York was particularly noted to be a hotbed of pro-Southern sentiment. And, then as now, was noted for its arts scene. (Remember, John Wilkes Booth was an actor.)

DC was another very pro-slavery city. While they didn't have the ability to vote in presidential elections, they largely supported Breckinridge, the most pro-slavery option. There was no significant Republican presence in the city on Lincoln's election and Lincoln had so little confidence in the city's loyalty that he hired private security to help him get into the city for his inauguration.

Often US textbooks mention the belief of Abolitionists that the government was controlled by a sinister "slave power." But they often do a very bad job of describing why Abolitionists thought that. Abolitionists, searching for a reason they hadn't been successful despite winning elections, knew that many American elites and the important cities like DC were pro-slavery. Slave power was the idea that pro-slavery advocates used bureaucratic, partisan, and cultural power to pressure or persuade Abolitionist politicians to not push the Abolitionist cause. Or, failing that, to sabotage their initiatives.

A classic (and charged) example was the tendency of American social climbers to convert from low church religions like Methodism to Episcopalianism, the traditional religion of the American elite. Episcopalianism was one of the more slavery tolerant denominations. In a time when a lot of politics was done from the pulpit, the transition from an anti-slavery to a moderate or pro-slavery church was significant.

Lincoln failed to make these transitions, failed to conform to standard elite expectations. And this was a political advantage for him, especially among Abolitionists. This was by no means a unique innovation: other American reformers like Jefferson and Jackson had similarly struck a populist pose. But it represented a challenge to the elite consensus of the time, including the cultural consensuses that made up the difference between the urbane and the gauche. And like previous reformers there was a reaction, including culturally against his supposed coarseness.