Hillary can also take advantage of voters who want a female president and aren't picky about who. She can also take advantage of the so-called "war on women" and the outrage against Republicans over it.
But before she gets fitted for her inaugural dress, let's go over her negatives:
Her age and health
Hillary is getting old. Her supporters have tried to defuse this by pointing to President Reagan's age and claiming sexism. The fact is that Reagan's age was an issue in both 1980 and 1984 when he ran for reelection. Age was also a factor for Bob Dole and John McCain.Hillary's health is also a valid issue. Her husband, Bill, has had major heart problems. She falls a lot. One of those falls was so bad that she had double vision for a month and had to wear corrective glasses. Other health issues may come to light.
Foreign Affairs
Hillary was Secretary of state. Many of today's problems began during her tenure. She was personally involved with the reset with Russia. If things continue to go wrong in the Ukraine, Iraq, Egypt, Lebanon, Afghanistan, or Syria, she will have to spend her time excusing herself instead of running.
Obama Fatigue
President Obama is not very popular right now. As a Democrat and former member of his cabinet, Hillary will be seen as running for an Obama 3rd term. McCain did well running against Bush as well as Obama but he was already known as a maverick and had no direct ties with the Bush administration. Hillary was a member of the Obama administration so it will be much harder for her to run against him. At the same time, a significant portion of Democrats still support Obama and Hillary will need their support to win the nomination. It will be difficult for her to do an about-face in the general election.
Clinton Amnesia
It's been a long time since the Clinton's left office. Hillary's appeal in 2008 was the promise to turn things back to the peace and prosperity of the 1990s, before 9/11 and the Bush wars. Promising to turn the clock back 16+ years will just make Hillary seem old and out of touch.Younger voters do not have clear memories of the Clinton years. Some voters weren't even born when Bill took office and anyone under 30 will barely remember the Clintons.
Clinton Fatigue
2012 was the first election since 1976 that didn't have a Clinton or Bush running (I"m including Hillary's primary run in this). 2016 may have both a Clinton and (Jeb) Bush running. A lot of people are tired of these political families.While voters under 30 didn't really know the Clintons, the ones over 30 were sick of them by the time they left office. We don't really want to be reminded of Vince Foster, Whitewater, blue dresses, etc.
Hillary Herself
In 2008, the presidency was Hillary's to lose. She was the clear front-runner with all of the advantages she has today (her resume was a bit thinner) and fewer of the disadvantages. Regardless, she managed to lose. A quick recap is in order.Hillary began the campaign with a sense of inevitability. Her campaign was built around this. She had a huge campaign fund and she spent it with the idea of wrapping up the nomination by Super Tuesday. She concentrated on delegate-rich states and ignored caucuses in smaller states. She did win the most delegates on Super Tuesday but not enough to give her the nomination.
In contrast, Obama had a 50-state campaign. His supporters were more excited and managed to shout down Hillary supporters in caucuses. Obama won a string of caucuses unopposed after Super Tuesday while Hillary restarted her campaign. The air of inevitability moved from Hillary to Obama. At the end of the primaries, neither candidate had a majority of the delegates but Obama's string of victories assured that he got the nomination.
Hillary probably learned her lesson in 2008 and won't let herself be outmaneuvered like that again. Regardless, 2008 shows flaws in her judgement.
Another lesson from 2008 is that Hillary isn't a very good campaigner. She comes across as shrill and insincere. She does best when she runs as a concept rather than as a candidate. Her popularity suffered a slight drop when she entered the public eye again on her book tour.
Summary
Hillary's biggest asset is her inevitability. That will let her raise huge sums and garner a lot fo votes from people who have been waiting years to ratify her.At the same time, she suffers from staleness. It is likely that a Republican governor will be the candidate and will seem young and fresh in contrast. We saw in 2008 how easily Hillary could lose her inevitability.
History says that the Republicans have a very strong chance of taking the White House. It tends to change hands after a 2-term president. The Republicans could still falter and nominate a candidate who makes Hillary look good but, all things being equal, Hillary's chances are slim.