The first National Tea Party Convention was held last weekend in Nashville, Tenn. The Tea Party movement resulted from grassroots rallies energized because of expansions of federal power during the last years of President George W. Bush’s administration and the beginning of Barack Obama’s presidency.

Consistent with the movement’s early concerns, the convention’s speakers pledged adherence to individual liberty, limited government, fiscal discipline and other worthy constitutional principles. And they expressed disappointment that neither the Republican nor Democratic parties share the Tea Party activists’ attachment to these ideas.

The Tea Party organizers claim to seek a 21st-century revival of the spirit that motivated Bostonians to dump British tea into Boston Harbor in December 1773. If we look at history, there are parallels, but also there are differences.

To appreciate the Boston Tea Party, one must understand something about the British Constitution. Because it was unwritten, the British Constitution necessarily relied more on custom or precedent than the modern U.S. Constitution.

When subjects feared that Parliament or the king were inserting a dangerous innovation into the constitutional order, they were compelled to create a “record” with protests. If they failed to do so, a subsequent king or parliament could build on the precedent.

The Boston Tea Party is a prime example of the importance of precedent. Though the Tea Act of 1773 reduced the price of tea, the colonists felt compelled to take action to prevent Parliament from setting a revenue precedent. Under commercial rules, a ship entering a colonial harbor was not permitted to leave without offloading its cargo. If the tea was offloaded, a tax would be paid. If it was not offloaded within 20 days, the cargo would be seized by customs officials who would retain a portion of the merchandise to satisfy the tax.

The Boston Tea Party occurred on the 19th day that the ships bearing tea had been in the harbor. The colonists destroyed the tea so it could not be seized by customs officials and the duty technically “paid” to create a precedent.

With this understanding of precedent, new light is shed on the Boston Tea Party and its modern counterpart. Like Boston patriots, the Tea Party movement is working to halt the creation of dangerous precedents. Tea Party activists comprehend the “ratchet effect”—that is, once government expands its power and new bureaucracies are in place, it’s difficult to undo them.

Nonetheless, a fair criticism is that the Nashville convention attendees are, pardon the pun, late to the party. Long before Bush signed the bailout in 2008, his administration favored one-size-fits-all federal solutions and increased federal power.

The Tea Party was correct to take aim at the bailout legislation, but one wonders where the Tea Party leadership was when Bush created harmful precedents by pushing for a new Medicare prescription drug benefit and the No Child Left Behind Act.

For the American patriots of the 1760s and 1770s, it did not matter whether King George III’s government was headed by a Tory such as George Grenville or a Whig such as William Pitt. The colonists consistently fought efforts by the British central government to expand its power.

The modern Tea Party now appears to understand what Samuel Adams and John Hancock took for granted: Government power often tramples fundamental rights no matter who is in power—Whigs or Tories, Republicans or Democrats.

Accordingly, what we should take from the Tea Party’s recent convention is that principles of individual liberty and limited government must remain inviolable no matter what party is in the White House. Otherwise, dangerous precedents will be set that are difficult to undo.