Has anything like the Bush-Gore deadlock occured before? Yes, it has. The winner's prospects for a mandate to govern are very bad, and the loser's prospects in 2004 are very good, judging by history....
Jackson started mobilizing political support, helped by Vice President Calhoun (Vice Presidents were not necessarily from the same party then). Together, they formed the Democratic party with support in both north and south.
Jackson won the "rematch" election of 1828 with 56% of all votes. He portrayed himself as the "people's president."
However, 20 electoral votes were being disputed, all but one in the southern states of Louisiana, South Carolina, and Florida. Congress created an electoral commission, consisting of five senators, five representatives, and five Supreme Court Justices. There were eight Republicans and seven Democrats on the committee. All voted along party lines, and Hayes won. Democrats threatened to stop the Senate from officially counting the electoral votes, thus preventing the inauguration. The country was in crisis, but a compromise was reached. The Democrats agreed to suspend resistance to counting of the votes, and Hayes became president, winning the electoral college by one vote.
In return, Hayes ordered the last troops to leave the south, appointed a former Confederate general to his cabinet, supported federal aid to encourage economic and railroad development, and left the south alone to manage race relations - in other words, Reconstruction was over, and Hayes did not enforce the 14th and 15th amendments. So, the national crisis was averted, but the days of Jim Crow had begun.
Hayes' tenure as president was dogged by taunts of a fraudulent election victory, calling him "Ruther-fraud B. Hayes."
In 1888, Benjamin Harrison beat Grover Cleveland. Harrison got 47.9% of vote, and Cleveland got 48.6%. Harrison won the electoral college, 233 to 168. Cleveland came back in 1892 to win the election, making him the only president to have served two non-consecutive terms.
The most remarkable attribute of presidents in this era of tight races is that none of them had remarkable accomplishments as president. Some of their unremarkableness can be attributed to a relatively more powerful Congress at that time, and some can be attributed to the weakening of the federal government as a whole, resulting from the aftermath of the Civil War. But certainly some of the weakness of the presidents in this era can be attributed to the weak mandate they received at the voting booth.