Both parties are increasingly concerned about their respective wings. Heading into 2016’s presidential race, the Democratic and Republican establishments have only a tenuous grip on their core ideological supporters. They are right to be worried. Damage there in the primaries could be hard to overcome in next November’s election.

For mainstream Democrats, Hillary Clinton is the anointed one — predestined to be president. For Republicans, she is the liberal they love to hate. For increasing numbers of Democrats, however, she is the liberal they most hate to love.

As 2016 approaches, Clinton is threatened with being the Democrats’ bridesmaid again. Having lost to her party’s left in 2008 — then led by Obama – according to mounting evidence, she is losing to it again — this time, enthralled by Senator Bernie Sanders.

Hillary can seem to only capture Democrats’ head, but not their heart.

Republicans are experiencing the same thing, but in a very dissimilar way. Where mainstream Democrats pursue liberals with one candidate, Republicans are pursuing conservatives with many. Yet despite a multitude of candidates giving chase, conservatives are proving just as elusive to regular Republican candidates.

Rather than splintering the right as might be expected with so many candidates, the right is scattering from conventional Republican candidates and coalescing around billionaire businessman Donald Trump.

Over a year away from the election, the threat is quite real to both parties because it comes from their core supporters.

National exit polling showed liberals comprising 25% of 2012’s voters. This quarter of America’s electorate voted 86% for Obama. Of all the groups broken out in this polling data, only Democrats (92%) and blacks (93%) voted for Obama in higher percentages.

Put another way, Democrats were 38% of voters. If all the liberals who voted for Obama had been Democrats, they would have composed roughly 57% of the Democrats voting.

The same exit polling showed conservatives to be 35% of 2012’s voters. Eighty-two percent of these conservatives voted for Romney. Of all the groups recorded, only Republicans voted in a greater percentage for Romney.

Again to illustrate their political party throw-weight, Republicans made up 32% of 2012’s voters. If all the conservatives who voted for Romney had been Republicans, they would have comprised almost 90% of that party.

Liberals and conservatives, respectively, are among Democrats’ and Republicans’ largest, most dependable, and most motivated voters. This is why Sanders and Trump have been able to amass such significant support so quickly. It also shows why their support is such a threat to their respective party’s establishment.

Taking support from the party’s core means any loss there must be made up among less dependable voters — such as Independents — in the general election. In 2012, Independents were just 29% of voters and they split almost evenly — 45% for Obama and 50% for Romney.

And in the primary elections, where Independents will vote in far smaller numbers, losses in a party’s ideological base are even tougher to overcome.

The threat the parties face to their core supporters is threefold. First, is the threat that their preferred mainstream candidate could lose outright in the primary battle — just as Hillary did in 2008.

Second, even if a mainstream candidate wins their nomination, it is possible a non-mainstream candidate so motivates their ideological core in the primaries that these voters won’t be interested in the mainstream nominee in the general election.

Finally, in order to win the nomination, their mainstream candidate could have to work so hard in the primaries to retain core party supporters that their nominee will be compromised in the general election — having pushed away the Independent voters needed to win.

The Democratic and Republican parties are in the same political pickle. Without control of their core supporters, they do not have control of their political fortunes. Currently 2016, rather than looking like a race either party could win, is looking like one both parties could lose.