“The” political spectrum is a set of views on various positions the evolves from the continuing efforts of the two major parties in a U.S.-like two-party system to gain a political advantage. (The U.S., by the way, is the only country in the world with a U.S.-like two-party system.) In this evolution, there are elements of continuity and change.
Jeffersonian Republicans (renamed Democratic Republicans by historians) favored state versus federal government, and freeholders versus manufacturers and bankers. They also favored free trade and the commodity money. Up to the War of 1812, they were inclined to side with France in the interminable conflicts between England and France through the Napoleonic period. In some ways, they were conservative by the present definition of conservative.
Jacksonian Democrats (or simply Democrats), similarly to Jeffersonian Republicans, favored state versus federal government, but were radical. As stated by another, they were for nullification of federal acts. They were also for nullification of court decisions. They did not think a constitution or lifetime judges should stand against the will of the people (at least not as they saw the will of the people). They, like their predecessors, favored free trade and the gold standard. Here, again, they went radical with regard to banks and debt. In Mississippi, they outlawed banks and repudiated debt. Virginia was not only a border state geographically, its Democratic Party never bought into the radical wing of their kin in the deep south. By the time the Jacksonian Democrats emerged, we were in Pax Britiania, so siding with one or the other European power was not an issue. You can see that the conservatism that marked the Jeffersonian Republicans is mixed with radical elements in the Jacksonian Democrats.
The rise of progressivism marked another shift. During the election of 1896, William Jennings Bryan’s brand of radicalism eclipsed the so-called Bourbon or conservative wing of the Democratic Party. Although Bryan lost that election, the Democrats shifted from gold to silver and/or paper money, and from supporting a private-property based, free enterprise system to advocating a progressive income tax and regulation of the economy. They continued to advocate free trade, but this may have reflected the interests of their voters, many of them being farmers. By the time of Woodrow Wilson, getting sucked into European wars in the name of peace and democracy was also part of the agenda. Wilson combined the racism of the Jacksonian Democrats with the pseudoscience of eugenics, as developed in the replacement of Biblical teaching on the basic equality of all human beings with Darwin’s idea that we evolved from monkeys, and some of us not completely.
Modern Democrats take all the bad things of Wilson and make them worse and, furthermore, argue that White people and Jews have evolved too much and are to be hated because of their superiority. They will add Asians to the list of people to hated as soon as they figure out how far evolved they are. I, clinging on to my guns, my Bible and my Constitution, continue to believe that all men are created equal and that the observed differences among the peoples of the Earth reflect natural selection to local conditions not much important to the economic circumstances of today.
Well... first, through the life of Jefferson himself I consider the following parties to be all one, all Democrats:
Until very recent decades Democrats were based in the Solid South, Republicans in the less-than-solid North.
Today Democrats still have a Solid South component, but flipped from whites to African Americans.
I say that it's vastly more helpful to think of Democrats as one long history from 1787 to today -- opposed to the Constitution, favoring more Federal power when they rule, berserk lunatics when out of power, and often favoring party over country.
Federalists-Whigs-Republicans have nearly always been the more Conservative constitutionalists, certainly when compared to radical Democrats.
You disagree?