Although Democrats hold a very substantial edge in voter registration—53% of registered voters to the Republicans' 33% as of 1998—New Mexico has been a "swing state" in US presidential elections since it entered the Union. Between 1948 and 1992, New Mexicans voted for Democratic presidential candidates four times and Republican presidential candidates eight times, choosing in every election except 1976 and 1992 the candidate who was also the presidential choice of voters nationwide. In the 2000 presidential election, Democrat Al Gore beat Republican candidate George W. Bush by a mere 366 votes, out of approximately 615,000 cast statewide. In 2002 there were 950,274 registered voters. The state had five electoral votes in the 2000 presidential election.
New Mexico's US senators in 1999 were Democrat Jeff Bingaman, elected in 2000 to his fourth term, and Republican Peter V. Domenici, who was elected to his sixth term in 2002. Following the 2002 elections, New Mexico's US House delegation consisted of two Republicans and one Democrat. As of mid-2003 there were 24 Democrats and 18 Republicans in the state senate and 43 Democrats and 27 Republicans in the state house. Governor Bill Richardson, Democrat, was first elected in 2002. He had previously served as a US Representative, UN ambassador, and Energy Secretary under President Bill Clinton.