Barack Obama has catered to the 3 main left-wing groups dominating the Democratic party: they include pacifists who oppose military intervention, free spenders who believe that the answer is always more government spending, and apologists for the African-American sub-culture that produces academic underachievers and violent criminals. To the pacifists, he has pledged to never attack another nation unless it directly threatens the USA. So, an Obama-ian response to the Serbs' slaughtering the Kosovars in 1999 would have been to ignore the victims. To the free spenders, he has promised to raise taxes: eliminating the cap on payroll taxes and likely hiking the capital-gains tax rate from 15% to 28%.  He will pour some of this new revenue into primary and secondary schools even though we already spend 31% more per student than even the education-obsessed Japanese.  To the apologists, he has offered 20 years of attendance in a church preaching hatred against European-Americans and blaming them for all that ails African-American society.
This 3-pronged electoral strategy has been successful. A majority of young adults (who lack knowledge of history and current events, according to numerous studies), college students (with "higher" education having been a bastion of peaceniks for decades), and wealthy liberals (who have the money to waste on higher taxes) has consistently supported Obama. An overwhelming majority (roughly 90%) of African-Americans has flocked to Obama. He is now mere weeks away from winning the Democratic nomination.
We are witnessing the coronation of another Ned Lamont. Like him, Obama does not represent the views of mainstream America. While most Americans oppose unsuccessful military intervention like the current occupation of Iraq, the very same Americans support successful military invervention: e.g., the Gulf War in 1991 and the NATO-led police action against Serbia in 1999. Also, most Americans oppose increasing taxes to grow the size of government as numerous politicians can attest that they gained political office by pledging "no new taxes". Of course, blaming European-Americans for African-American failure just does not resonate with non-African-Americans, who comprise 88% of the United States and who have witnessed millions of immigrants succeeding without blaming European-Americans.
If Obama is Lamont, then Hillary Clinton could be Joseph Lieberman. Propelled by left-wing groups, Lamont defeated Lieberman to win the Democratic nomination for the U.S. Senate. Still, Lieberman knew that he, unlike Lamont, enjoyed broad support in Connecticut. So, Lieberman bolted from his party, ran as an independent in the general election, and -- won.
Like Lieberman, Clinton has been sidelined by the left-wing groups but enjoys broad support across the American electorate. It supports fiscal conservatism like workfare-focused welfare, cautious social liberalism like "Don't Ask, Don't Tell", limited interventionism like the police action again Serbia, and free trade like that embodied by the North American Free Trade Agreement (NAFTA). This philosophy of government is precisely the one which she proactively helped her husband to implement when he served as president.
In a 1992 interview with Ted Koppel, she famously rejected "staying home and baking cookies" and effectively became chief adviser to her husband. His government policies are her government policies. Though the left-wing groups dominating the Democratic primaries have forced Ms. Clinton to distance herself from his policies, her voting record in the Senate affirms her commitment to a continuation of them. For example, despite criticizing free trade on the campaign trail, she actually voted for free-trade agreements with both Chile and Singapore in 2003, dovetailing his support for NAFTA in 1993.
These policies are the reason for her popularity in mainstream America. Even conservative commentators like Ann Coulter and Bill Cunningham have declared support for Clinton. So, if she entered the presidential election as an independent candidate, she would likely win a 3-way race among John McCain, Obama, and herself -- just as her husband and Lieberman won their 3-way races in 1992 and 2006, respectively. However, before she can even entertain the idea of running as an independent, Clinton must ask herself whether she has (1) the confidence to win and (2) the courage to burn all her Democratic bridges.
1. The essay, "Hillary Clinton as an Independent Candidate", was originally written in 2008 May.
2. Kimberley A. Strassel at "The Wall Street Journal" concurs with most of the key points in the above essay. 
3. During the 5-year period ending on 1998 April, President Bill Clinton reduced the number of civilian employees in the executive branch by about 330,000. He reduced "the number of federal government employees to a level lower than any time since the Kennedy administration". 
4. The Democratic Leadership Council, of which Hillary Clinton is a member, advocates "free trade, personal accountability and a strong national defense". 
5. Barack Obama opposes using the American military to protect the victims of genocide. 
1. "Obama's Tax Evasion", "The Wall Street Journal", 2008 April 18.
2. "Education Indicators: An International Perspective", U.S. Department of Education, 2003.
3. "Transcript of Thursday's Democratic presidential debate", CNN, 2008 January 31.
4. Curtis Brainard, "Obama’s NASA Plan Gets Little Play", "Columbia Journalism Review", 2007 November 29.
5. "National Geographic-Roper Public Affairs 2006 Geographic Literacy Study", The National Geographic Education Foundation, 2006 May.
6. Ted Koppel, "Making Hillary Clinton an Issue", ABC News, 1992 March 26.
7. "The U.S. Congress: Votes Database", "The Washington Post", 2008.
8. "Hannity and Colmes" (interview with Ann Coulter), Fox News, 2008 January 31.
9. "McCain apology angers conservative host", CNN, 2008 February 27.
10. Kimberley A. Strassel, "Farewell, New Democrats", "The Wall Street Journal", 2008 June 20.
11. Donald F. Kettl, "Reinventing Government:
A Fifth-Year Report Card", Brookings Institution (Center for Public Management), 1998 September.
12. John Fund, "The Keepers of Clintonism", "The Wall Street Journal", 2008 July 3.
13. James Taranto, "'It Didn't Happen'", "The Wall Street Journal", July 26, 2007.