Chapotraphouse

It's because in like the 1820s they expanded voting rights from (generally) "White landowners" to "White landowners and taxpayers". Heck, even Maryland Jews could vote! We're talking about an expansion from 3% to 9% of people over the decade lol.

So anyway, all these freedom loving crackers got together and voted for Andrew Jackson in 1824, who won the popular vote and the most electoral votes. Back in that time, however, there were multiple candidates! And the dumbass law was that if no candidate won an outright majority of electoral seats then congress gets to pick who actually won. Imagine if Zohran won the election with 49.9%, and NY congress just went, "Okay Cuomo wins!"

Everybody got pissed and ran it back in 1828, and thanks to the background of expanded voting rights, Jackson swept the competition. It was known as the party of Jacksonian Democrats and the rest is history.

They are called that because Andrew Jackson was pro universal white male suffrage (previously there was a wealth requirement).

Before that was the Democrat-Republican party (Andy J was divisive and killed the party) was organized as an opponent to the federalist party who were pro centralization. At the time Members of Federal Congress were appointed by the states so the name Democrat-Republican was somewhat accurate.

They haven't changed their name b/c their branding is still that they are the party "of the people"

Edit: the D-R party was formed during the era of good feelings (after the federalists fell apart), it was the (Jeffersonian) Democrats who were organized in opposition to the Federalists.