Because the Federalists had horse****ed themselves by implementing policies that were blatantly against the Constitution of the United States.
Or the American people were voting for candidates they actually wanted, rather than voting defensively, as many do today.
I mean, sure, the Democratic-Republicans managed to hold on to the Presidency in 1824 and 1828 - but only members of the Democratic-Republican Party were running.
And that was due to popularity and a general consensus among the people that the government was following the original intent of the Constitution. Not like today when the two major parties have all sorts of laws in place to limit their competition. Competition was completely free and open - no one bothered due to the fact that they felt Jefferson's party was doing its proper duty and defending the unalienable rights of the citizenry.
The disaster to which I'm referring is the Embargo Act. Economic depression, widespread smuggling...yeah, that worked well.
No, it didn't work. It was a hasty decision made due to war in Europe, and it was a mistake.
But at least his intentions were to try nonviolent resistance first. And unlike other Presidents such as Bush, Jefferson actually admitted that it didn't work and signed the Non-Intercourse Act two days before he left office to effectively nullify the Embargo Act.
Jefferson made mistakes, I just think he made less than other Presidents.
Perhaps it wasn't done due to monetary reasons. It was still done.
The main issue with the War of 1812 was that we didn't lose. Therefore, whatever harm anyone claims was done to the military, did not affect the independence of the country. Our military wasn't set up to declare and wage an offensive war. Our national militia was a purely defensive measure.
Jefferson could have used the "bully pulpit" to prepare people for war earlier and urged all Americans to stockpile ammunition and make sure they were armed. He also could have urged for voluntary training measures and local drills. Madison could have done this as well after realizing Jefferson's embargo measures failed. I think they all had a sense the war in Europe could draw them in at any time.
But the fact remains - any private ship that enters into war zone takes full responsibility for doing so. And the government should have made this abundantly clear to people - that was another failure of Jefferson's. They should have put out constant notices to people telling them "you risk EVERYTHING if you send goods overseas during a war." The government has no obligation to protect private citizens or private goods that leave the country.