Both the Democrats and the Republicans like to think of themselves as the true heirs of Thomas Jefferson. The modern Democrats are historically descended from the Democratic-Republican Party that Jefferson himself organized to thwart the ambitions of Alexander Hamilton (although, ironically, they were known as "Republicans" in Jefferson's time). Democrats around the country annually celebrate Jefferson-Jackson Dinners, avowedly declaring a connection between Jefferson and the modern Democratic Party. But Republicans claim that their platform of small government and low taxes is more in line with true Jeffersonian philosophy than that of the big-government Democrats.
So, let us ask ourselves this: if Jefferson were alive today, would he be a member of the Democratic or Republican Party?
The answer: neither.
Let's begin with examining why Jefferson wouldn't have been a member of Republican Party. Firstly, Jefferson was a strict believer in the "wall of separation of church and state". Indeed, he coined the term himself in his famous letter to the Danbury Baptists. Needless to say, the modern Republican Party does not share this position, as it is largely dominated by a group of people who clearly disdain the separation of church and state. Had Jefferson seen the efforts by the Religious Right to subvert science education, enforce religious standards for judicial nominees, divert taxpayer money to religious institutions, and use the power of government to regulate personal moral behavior, Jefferson would have been horrified. Indeed, he likely would have considered the Religious Right the most dangerous people in America.
Secondly, Jefferson believed in keeping military expenditures minimal and holding to a largely pacifistic foreign policy. The modern Republican Party, by contrast, believes in pouring gargantuan amounts of money into a vast military-industrial complex, including military projects of huge expense and very dubious value. In a time of severe budget pressures and rapidly mounting national debt, this policy has contributed to the bankruptcy of the nation.
Furthermore, Jefferson believed that war should only be resorted to if absolutely necessary; indeed, he strenuously avoided war with Britain in 1807, even when the entire country was clamoring for it. By contrast, the last Republican administration almost gleefully invaded Iraq, a country that had not attacked the United States and had no plans to do so. Jefferson would have supported the campaign in Afghanistan, which was undertaken in response to a direct attack (and in which we can see parallels with his campain against the Barbary Pirates), but he would have fiercely opposed the invasion of Iraq as an unnecessary war of choice, and it would have tainted the Republican Party in his eyes.
Jefferson would have agreed with the planks in the Republican platform calling for lower taxes, smaller government, and balanced budgets. But he would immediately have noted that, during their years in power, the Republicans singularly declined to implement their own stated policies. Indeed, they massively increased the size of government and transformed a sizable budget surplus into an immense budget deficit.
There are more areas where Jefferson would have fundamentally disagreed with the Republican Party, from warrantless wiretaping to blatant cronyism in government appointments (remember this guy?). But the most obvious reasons Jefferson would never have been a Republican are the fact that the party is largely controlled by the Religious Right and its militaristic attitude to defense spending and foreign policy.
So, Jefferson would obviously not be a Republican. Would he, therefore, be a Democrat?
No, he wouldn't. Jefferson would have firmly rejected the Democratic Party's over-reliance on the power of the federal government, whose powers Jefferson clearly believed should be strictly limited. The vast powers of modern federal institutions would have dismayed Jefferson, who would have believed that they sap the self-reliance of the people, and therefore indirectly sap their liberty.
A few quick examples should make the point. Jefferson would have asked why we have a federal Department of Education; shouldn't educational issues be decided on a purely local level? He would question the purpose of a federal Substance Abuse and Mental Health Services Administration, when a truly self-reliant people would be expected to deal with such issues on a community level, without resource to the government at all. And do we really need the federal government, rather than the German-American community, to declare October 6 to be German-American Day?
Jefferson believed profoundly that government at all levels should be limited only to activities that meet two criteria: 1) activities which are necessary, and 2) activities which only the government alone can do. If an activity is not necessary, then the government shouldn't bother with it. And if an activity can be done by ordinary people without recourse to the power of government, then the people should do it on their own. The modern Democratic Party does not feel the same way, as demonstrated by the whirlwind of federal programs they constantly propose and create, and this is the main reason that Jefferson would spurn them.
Jefferson also would have strongly opposed the current policy of President Obama and the Democratic Congress of incurring massive federal budget deficits, leading to a shocking increase in an already-disastrous national debt. Granted, the Republicans took a budget surplus and foolishly blew it, but President Obama's spending in his first year in office is much higher than spending was in any year of the Bush administration. Looking at this, the Shakespearean line "a plague on both your houses" would certainly have crossed Jefferson's mind.
The 21st Century Jeffersonian is not necessarily a Republican and not necessarily a Democrat. He or she participates fully in politics on all levels, but judges each candidate on his or her individual merits. And if 21st Century Jeffersonians believe that none of the candidates in a given election truly represent their values, they should step up to the plate and run for office themselves.