To win the presidency, the Democrats have to do better in the South, the Lower Midwest, or the interior West. Furthermore, governors do a lot better than senators. Add to this the fact that Hispanics are the fastest growing ethnic group in the country. Enter Bill Richardson stage left, the Hispanic governor of New Mexico, who previously served in Congress, was ambassador to the United Nations, and was Bill Clinton's Secretary of Energy. Richardson's mother is Mexican and he grew up in Mexico City, so he speaks fluent Spanish. He just won reelection with 68% of the vote, the largest gubernatorial win in the state's history. He is well-known in the region and a Richardson candidacy could potentially bring in New Mexico, Arizona, Nevada, and Colorado, all of which have sizeable and growing Hispanic populations. Of course, against John McCain, they cancel each other on the the regional aspect.
Information from Electoral-vote.com
Information from Electoral-vote.com