By Donna Brazile, NEA Columnist

The Republicans have the largest candidate field for president in memory. The Democrats, on the other hand, may end up with only three serious contenders: Former Secretary of State Hillary Clinton, Sen. Bernie Sanders and Vice President Joe Biden. And a Biden run is only speculation at this point.

Leading in the New Hampshire polls for Democrats is Hillary Clinton. Her advisers need to continue to keep foremost in their minds that this is 2016, not 1996, when her husband, Bill Clinton, was last elected. This is going to be an election, not a coronation. So far, Hillary Clinton's campaign seems to have a hard time getting any positive news.

But if anyone on Hillary's team is even thinking of ignoring the Democratic primary voters and running a general election campaign, then her campaign is heading for a train wreck.

By running a general election campaign this early, she would fuel momentum for Sanders, a long-shot insurgent who is doing surprisingly well against her. Hillary has to stiff-arm Sanders' candidacy while embracing his progressive followers, a move requiring enormous political flexibility.

Hillary (and serious contenders in both parties) needs to address President Obama's 2015 State of the Union challenge: How to ensure that all Americans share in the economic recovery. Some interpreted his address as a challenge to the Clintons, but Obama implicitly praised Bill Clinton's record by citing 1999 as the best year for the economy in recent memory.

Voters have short-term political memories. It's political professionals, like myself, who recall the daily assaults on Obama's recovery efforts as "job killers" and the false claims that his stimulus produced "zero jobs."

Clinton needs to stay on course, and continue to insist that all Americans share in the recovery. The Republican policies that put millions of American families on a personal austerity budget of hot dogs and chili are waiting in the wings.

Also waiting in the wings are Hillary's opponents, both Democratic and Republican, who hope to capitalize on an issue, any issue, that will knock her out of contention. Many hope that particular issue is Clinton's use of a private computer server, and private emails, while secretary of state.

It isn't the actual facts about the emails that are important to the politicians. Most voters do not know the details of her private server emails. Rather, what is being sold is the perception that something wrong was done.

Combating a shadow is the hardest job for a candidate. Right now, Hillary is boxing her own shadow, albeit a shadow that is gleefully distorted by her opponents' spotlights.

Neither that shadow, nor the polls (which show some Clinton slippage), are her problem. We are 15 months from Election Day in November 2016. Today polls are entertaining snapshots of a race that is far from being in focus. This far out, they are literally useless in predicting a winner.

No, Clinton's current troubles come from being the front-runner of 20-plus candidates, each one gunning for her. No other candidate has two House committees acting in tandem with the sole purpose of shooting down her candidacy. Congressional Republicans are using every lever of government that they control to try and see to it that their party controls the White House after this election.

The House select committee on Benghazi has morphed from Middle-East terrorism into the "Hillary Email Committee." Its chairman, Rep. Trey Gowdy, is a Republican politician who protests that he's just seeking truth -- yet permits leaks of parts of closed-door testimony that distorts what was actually said, and every week labels Clinton news statements as "false," when they are either demonstrably true or accurate within context.

Yet, for those who hope to spring traps for Hillary, hope springs eternal. If voters believed Harry Reid's false 2012 claim that Romney didn't pay taxes for 10 years, others will believe Gowdy. But here's the key: For a rumor, or a charge, to be believable, there has to be a kernel of credibility somewhere among all the husk layers. Reid's charge was believed because Romney flatly refused to reveal his tax returns.

Charges that Clinton has not been fully forthcoming about her emails stem from her natural desire for privacy. Resisting press inquiries is an ingrained, longstanding habit for Hillary. For instance, although Clinton published all her public-business emails, 50 percent of her emails were considered private and deleted. That allows opponents to endlessly speculate about what was in them.

Clinton's only recourse is to vigorously confront the hypocrisy of the Benghazi probe, both over the emails and the response to the terrorist attack. That will keep her in fighting form right up into the thick of the race. Maybe getting her dander up is the biggest campaign boost Gowdy can gift Clinton.

Right now, let's see what happens during the debates. Someone is always lurking in the shadows -- waiting in the wings.