Faced with an unpopular nominee in Hillary Clinton, it's become pretty clear how Democrats plan to win the 2016 election — by painting a frightening portrait of a Donald Trump presidency.

But making the election about the implications of Trump's turbulent behavior will make it harder for Clinton to claim a policy mandate, complicating her liberal agenda as president should she win the election.

Throughout the Democratic convention, the appeal made to undecided voters was that Clinton was a stabilizing force, in stark contrast to the temperamental Trump. Former Mayor Michael Bloomberg made the case to independents that Clinton, as opposed to Trump, was a "sane, competent person." Clinton herself argued that, "A man you can bait with a tweet is not a man we can trust with nuclear weapons."

In the time since the convention, Trump, who got dragged into a war of words with the Muslim parents of a fallen U.S. soldier, has been regularly described as "erratic" and, according to President Obama, "unfit" to serve as president.

As Vox's Ezra Klein put it, Trump's nomination has ensured that the election would not just be about a Republican candidate vs. a Democratic candidate, but about "normal vs. abnormal."

The campaign against Trump seems to be working. Polls conducted after the conclusion of the conventions have shown Clinton gaining traction both nationally and in key battleground states. She is returning to the comfortable leads she enjoyed before the race tightened following the FBI's conclusion that Clinton was "extremely careless" in handling highly classified information as secretary of state, and was not truthful with the public.

However, making the case against Trump is easier than convincing Americans to embrace a sweeping liberal policy agenda. And Clinton has attempted very little of that.

Yes, it's true that Clinton has rolled out a number of policy ideas, and spoken about them. But the policy portions of her speeches are more about preaching to the converted and reassuring core Democratic constituencies that they can count on her than it is about attempting to persuade unaffiliated voters.

Clinton embraced what socialist Sen. Bernie Sanders celebrated as "the most progressive platform in the history of the Democratic Party." She told Sanders' supporters, "your cause is our cause." She has talked about expanding Obamacare and Social Security, making college tuition-free and debt-free, and raising taxes to subsidize childcare and family leave.

And maybe if Sen. Ted Cruz were the Republican nominee, this would set up an epic ideological clash in the fall between limited government constitutional conservatism and big government liberalism.

However, the fall campaign is not going to be about ideology or policy. It's going to be about whatever crazy things Trump says between now and Election Day.

Given where the race is headed, the most likely outcome of the election is this: Clinton wins as Americans reject Trump. But, despite a victory, she will still remain broadly unpopular and distrusted among a public that probably won't have paid much attention to her actual policy proposals.

There's no doubt that as president, Clinton will be able to preserve gains liberals made during the Obama era (such as on healthcare policy). She'll be able to make administrative appointments that will build on Obama's vast expansion of the regulatory state. And she'll be able to appoint at least one justice to tip the balance of the Supreme Court.

Though these are no small things, such outcomes will fall far short of the sort of "revolutionary" changes that passionate liberals drawn to Sanders were pushing for and that Clinton assured them that she'd pursue, albeit more incrementally.

This will put Clinton in a bind. Should she peruse a policy agenda to satisfy liberal activists, she'll be forced making her case to a public that's broadly distrustful of her and that mainly voted for her because they thought Trump was a nutcase.

However, should Clinton shy away from the type of policy agenda liberals have been pushing for, it will reopen rifts within the Democratic party, further weakening her political standing.

Liberals feel emboldened by the success they've had in moving Democrats decidedly to the Left on policy — and they can smell victory in November. But defeating Trump may not actually advance their ideas.