What lies ahead for Hillary Clinton

She's in! She's given up the private jet to schlep across America (albeit being driven by the Secret Service) and stroll, incognito, into Chipotle. Herewith, two myths about Hillary Clinton and two challenges for her on the campaign trail:

Ha! Do you know of any companies with monopoly power that urge competitors to come in and challenge their dominance? Didn't think so. If anyone understands the painful difference between a seemingly clear path to the nomination (Clinton 2008) and an actually clear path (Clinton 2016), it's her.

The downside of having an even quasi-serious, Democratic challenger is that it would pull Clinton to the left. That may be where Elizabeth Warren & Co. want her, but it's not where Clinton wants to be in a general-election contest. Consider the predicament of Jeb Bush, who has said he is willing to lose the primaries (except not actually lose lose) to win the general. Think he'd trade places with Clinton?

The theoretical upside of having a challenger is that it would provide a sparring partner to prepare her for the general election matchup and deflect some attention from what David Corn of Mother Jones calls the "around-the-clock Hillary Bashathon."

If you think Clinton's problem is that she may not be adequately battle-scarred, you have forgotten the 1990s or didn't live through them. Not tough enough is not her problem. As to the Bashathon, you think Republicans will ease up on her if they've got Martin O'Malley to kick around?

Not exactly. Campaign consultants debate whether the route to the presidency is to motivate (or expand) the base or to win over the vanishing pool of swing voters. When it comes to Clinton, the undecided pool is even teensier than usual: The percentage of voters with no opinion about Clinton — 4 percent in the latest Washington Post poll — is even smaller than those with a positive view of Congress.

Meanwhile, the hardest core of the Democratic base will probably never be over the moon about Clinton. As she applies policy prescriptions to the campaign theme that "the deck is still stacked in favor of those at the top," I suspect it will be insufficient to mollify the leftiest elements of the Democratic base.

Which brings me to two of the challenges ahead, one that is within Clinton's control, the other an immutable fact of political life.

Think about the most memorable, and most damaging, Clinton quotes over the years. "I could have stayed home and baked cookies." "I'm not sitting here — some little woman standing by my man like Tammy Wynette." "We came out of the White House … dead broke."

These were unforced errors that occurred when Clinton felt under assault. At those moments, she tends to bristle (understandable) and let it show (problematic). This vicious cycle of criticism and defensiveness is a tendency displayed by Bill Clinton, too, especially on his wife's behalf. This reaction is only human; far better is the more vulnerable human side of Hillary Clinton on display when she became teary during the 2008 New Hampshire primary.

Scrawled on a whiteboard in the Clinton 1992 war room in Little Rock was a campaign message from James Carville, "Change vs. more of the same." The American public's restive desire for change may be Clinton's steepest challenge; the shortlist (George H.W. Bush) of modern candidates who have won the presidency after a two-term incumbent of the same party suggests as much.

Voters want, in Obama's memorable phrase, "that new car smell." Al Gore lost the presidency (well, sort of) with Bill Clinton's approval ratings in the high 50s or above; Obama hovers under 50 percent.