In the election of 1800, the Republicans again backed Thomas Jefferson for president and Aaron Burr for vice president, while the Federalists supported John Adams for reelection. However, the Federalist Party began to fragment late in Adams' first term. Adams began to take a more moderate stance in response to public criticism of his policies, which distanced him from the so-called "High Federalists," more extreme politicians led by Alexander Hamilton. When these radicals suggested that Adams attempt to spark a civil war or declare war on France in order to bring voters to the Federalist side, he refused, instead choosing to govern as he thought was most helpful to the nation rather than fall into election politics. In fact, Adams had sent a second diplomatic envoy to France in 1799, much to the dismay of Federalist leaders. Federalists in Congress were outraged at the move, and Hamilton publicly denounced Adams as a fool. They were only silenced by Adams' threat to resign and leave the office to his vice president, Jefferson. Extreme Federalists withdrew their political support for Adams during the election due to what they saw as his compromising of Federalist ideals.
Republicans, for their part, were busy mobilizing in full support of Jefferson. They were quite successful in harnessing the popular dissatisfaction with the Federalists in power, and activated support in the swing states, Pennsylvania and New York. In those two states more than 50 percent of the eligible population voted. Almost 40 percent of voters turned out nationally, largely due to the efforts of Republicans to raise political awareness. In 1788, only 12 years earlier, only fifteen percent of eligible voters had gone to the polls.
The Federalists, in comparative disarray, nonetheless mounted opposition to Jefferson's campaign. They concentrated a negative campaign around the religious nature of the population in most Federalist strongholds, such as New England. Noting Jefferson was something of a religious free-thinker, Federalists actually used the campaign slogan: "GOD - AND A RELIGIOUS PRESIDENT; or impiously declare for JEFFERSON - AND NO GOD!!!" However, this appeal changed the minds of few Federalists who had abandoned the party. The Federalists struggled to find some way to capture the support of the nation beyond their traditional centers of support.
Adams lost the election of 1800 65 to 73 in the Electoral College. Republicans scored victories in New York, Pennsylvania, and unexpectedly, in South Carolina, a traditional Federalist stronghold, where Republican leaders had promised extensive political favors. However, all 73 Republican electors had voted for both Thomas Jefferson and Aaron Burr, who had been picked by the party to be vice president. Thus the Electoral College produced a Jefferson-Burr tie. The task of deciding who would become president fell to the House of Representatives. Burr refused to pull out of the race, even though he knew the party had chosen Jefferson as president. Federalists saw this as a chance to promote Burr over Jefferson, their arch-nemesis. Over six days, the House took 35 ballots, failing to choose either man with a majority of states. Finally, several moderate Federalists changed their positions, granted assurances that Jefferson would not obliterate all traces of the Federalist system. After 36 ballots Jefferson was president, and Burr, for his insolence, became completely impotent as vice president.
The most important factors contributing to Jefferson's victory in 1800 were the dissention in the Federalist ranks and the success of Republican organization and mobilization. Jefferson's Republicans proved adept at manipulating the press and keeping their fingers on the pulse of public opinion. They capitalized on the Federalist actions which had taken the greatest toll on the common voter, focusing particularly on the Alien and Sedition Acts as indicative of a Federalist desire to deny basic freedoms to the common man, and decried Federalist sponsored taxation as exorbitant and unnecessary. Adams was painted as a panicky figurehead controlled by an evil party which cared not for the average citizen. As a result of Republican efforts, voter turnout was greater than ever before.
The Federalists, meanwhile, mounted very little opposition, proving themselves much less capable of political organization than were Republicans. Their appeals to religious sentiment were almost laughable, and after Adams' decision to send a second diplomatic mission to France, they could no longer rely on the traditional claim that Republicans sympathized with France, the most prominent military threat to the nation. Additionally, with the probability of war declining, Americans grew incensed at the high taxes they were forced to pay to maintain the army. Under Adams, the national debt had swelled by $10 million, which further dismayed voters.