Forget population control. In 2016, the great cultural fad in American politics will be populist control. And it will be so popular, both parties will spend considerable time tamping down the populist momentum that threatens to upend their Congressional and presidential ambitions.

This past weekend, the American Conservative Union staged its Conservative Political Action Conference (CPAC), which it has hosted for more than 40 years in Washington, DC. CPAC attracts a full spectrum of the right, from individual grassroots activists around the country to the think tanks of the Beltway. Politicians range from Republican presidential contenders to libertarian and independent challengers for local office. The diversity of thought on the right gets put on full display, for better or worse, and CPAC allows the observant to see the trends on that side of the political divide.

The most obvious political trend in conservative and libertarian circles since 2009 has been the anti-establishment Tea Party. In the wake of the taxpayer bailouts of the finance and auto industries, the attack on crony capitalism in the nation's capital has only crescendoed over the six years since the 2009 cri de coeur from Rick Santelli. While the Tea Party may have been co-opted to some degree by the Republican Party and by "political circus barkers," as Salena Zito put it in January, the populist impulse on the right remains strong — and it showed at CPAC.

It didn't help the GOP, of course, that the Republican-led Congress botched its opposition to the highly unpopular Obama executive action on immigration by running up the white flag on DHS funding. After winning a second historic midterm election in a row, conservative activists expected the GOP to fight on the funding issue. Instead, John Boehner and Mitch McConnell kicked the can down the road with the "cromnibus" in the lame-duck session, promising a fight over DHS funding n February. On the second night of CPAC, McConnell shifted to fully funding DHS, while Boehner's attempt to get a three-week extension to regroup failed ignominiously. The House's final passage of the "clean" bill to fund DHS with no strings attached will only solidify conservative opposition to leadership.

Small wonder, then, that any hint of establishment got a hostile reception in the conference. Jeb Bush, whose hardball attempts to lock up the donor base and the consultant class got attention from The New York Times, bravely chose to make his case to a skeptical audience. Bush got a polite and at times warm reception for his honesty, but after his supporters left the room, the temperature changed radically.

The topic of the last panel of the conference was how to win in 2016, and any mention of Bush was met by a chorus of boos and catcalls. I know this because I was on the stage as part of that panel. Even a remark intended as a compliment to the CPAC crowd for treating Bush respectfully drew loudly negative responses. Bush has chosen to marry the political establishment to himself, and the grassroots have taken notice of it.

The populist pull may threaten Republicans less in 2016, though, for two reasons. First, they have more options for president, most of whom come from outside the Beltway, and even those who do — such as Ted Cruz and Rand Paul — are seen as anti-establishment, fighting against crony capitalism and the consultant class. Second, the anti-Washington tone of the populism fits the conservative agenda of smaller government and devolved powers through federalism.

The populism that is "alive and humming across America," as Zito puts it, will present bigger problems for Democrats in the next cycle. Their traditional agenda envisions a greater and more active role for the federal government, and therefore for Washington. Their presumed presidential nominee has been a creature of Washington for three decades. And even worse, their potential populist contender wants to make Washington even more central to the lives of voters than the overall Democratic Party agenda.

Hillary Clinton has thus far not drawn much opposition as she prepares to launch her presidential campaign. Eight years ago, although analysts thought the race was hers to lose, the former first lady got upended by a first-term senator from Illinois who promised to reform Washington as an outsider. Since then, she has only spent more time in Washington and further ensconced herself among the Democratic Party elite — not unlike what The New York Times reports that Jeb Bush has begun to do.

It will be difficult for Clinton to work within a populist culture that mistrusts Washington after having spent eight years there as first lady, another eight years as senator, and a final four years as secretary of State. Her family's foundation has close ties to the big Wall Street firms that progressive populists detests, and it turns out that it also took tons of cash from highly illiberal regimes like Saudi Arabia, Kuwait, Oman, and Algeria — while she was serving as secretary of State.

The alternative, though, may be worse. Progressive populists continue to push for Elizabeth Warren to challenge for the Democratic nomination, but Warren's policy preferences favor Washington-based interventions. Her biggest project, Dodd-Frank, was supposed to end Too Big to Fail, but a Harvard Kennedy School study shows that bank consolidations have accelerated because of the regulatory burden of Warren's law. Big banks are getting bigger while small community banks are disappearing, and agricultural loans are disappearing along with them.

In order to protect the Democratic Party's chances in 2016, the Democratic Party establishment has formed the New Democrat Coalition (NDC), which will take aim at the Warren wing of the party. Similar to the Democratic Leadership Council that once elevated Bill Clinton to the presidency, they want to produce candidates who will sound less like Occupy Wall Street and more like Main Street workers and business owners.

The Democratic establishment wants to tamp down progressive populism in favor of a top-down message that supports a top-down agenda. While the GOP may be internally dysfunctional at times, it at least has options to address its party's anti-establishment populism. Democrats appear ready to not only answer it with a candidate who's the ultimate establishment insider, but to shut down any populist impulse that might truly lead them to a more responsive posture. Either way, it's Washington or bust for Democrats, and that will be a tough sell indeed in this environment.