Three weeks out from the Iowa caucuses, and clarity emerges.

Hillary Clinton, the likely Democratic nominee, is in trouble.

Polls show her slightly ahead of socialist Bernie Sanders in Iowa, but narrowly behind in New Hampshire. And the weekend brought new revelations about yet more classified and secret documents sent over her private email server when she was secretary of state.

Between now and November, she will be traversing a minefield, with detonations to be decided upon by FBI investigators who may not cherish Clinton and might like to appear in the history books.

Clinton's charge about Donald Trump's alleged "penchant for sexism" brought a counterstrike – her being the "enabler" of Bill Clinton's long career as a sexual predator – that rendered her mute.

But with Hillary Clinton having raised the subject, it is almost certain to be reintroduced in the fall, if she is the nominee.

Then there is the newly recognized reality that Clinton, who ran a terrific comeback race against Barack Obama in 2008, is not the candidate she was. Nor is Bill the imposing surrogate he once was.

Both are eight years older, and show it. "Low energy" nails it.

Lastly, Hillary Clinton now has a record to defend as secretary of state, a four-year term in which it is hard to see, looking back, a success.

Moreover, a defeat by Sanders in Iowa or New Hampshire could prove unraveling, with the press herd tapping out early obits.

New Hampshire has consequences.

A Granite State defeat by Sen. Estes Kefauver ended Harry Truman's bid for re-election in 1952. Lyndon Johnson's narrow write-in victory over Sen. Eugene McCarthy, 49-42, brought Bobby Kennedy into the race – and LBJ's withdrawal two weeks later.

George H. W. Bush's unimpressive New Hampshire win in 1992 brought Ross Perot in as a third-party candidate two days later, and Bob Dole's loss in 1996 portended defeat in the general election.

But if a cloud is forming over the Clinton campaign, the sun continues to shine on The Donald.