Amid the balloons and the tensions on the floor of the conventions, it’s tempting to dismiss the parties’ platforms as musty, redundant and, let’s not forget, long. But you should pay attention to the platforms this year, because they are tea leaves to help predict the murky future of both Republicans and Democrats.

Even in a normal election year, platforms can be a useful source of information about whether parties do what they promise to do. And some political science research is emerging that suggests that platform positions offer an important clue to the policies that U.S. parties, despite our separation of powers system, will enact. One study, recently reported by Vox, found that party members in Congress voted in line with their platforms more than 80 percent of the time.

This year, the Republican platform reversed years of support for free-trade policies, instead embracing Donald Trump’s more protectionist stances. For the Democrats, platform influence was one of the concessions extracted by the Bernie Sanders campaign, and Hillary Clinton’s forces accepted support for a minimum wage of $15, a carbon tax and expansion of Social Security. The political science research offers a tentative argument that we might expect these changes to last.

Platforms also help political scientists understand how parties change. John Gerring, who used platforms as a major data source for his book on party ideologies, finds that once parties shift on big issues, such as the power of the federal government, those changes last for a while. Fairfield University political scientist Gwendoline Alphonso traces the changing language about families and well-being in Republican platforms and connects these changes to larger policy shifts.

American parties saw a couple of major transformations in the past century that were reflected in platform fights: In 1948, the adoption of a civil rights plank by Democrats spurred a major split in the party. In 1972, the Republican Party supported the Equal Rights Amendment, which would have made gender equality part of the Constitution. By 1980, this support had been reversed in favor of a more traditional take on gender issues. The Republican platform in 2016 may represent such a shift on trade issues. Both of these changes were the result of the growing strength of activists devoted to these issues within the party coalitions.

Issue positions aren’t the only kind of change we should look for in platforms.

The construction of the platform can give us some clues about which issues are most important to the party. Unsurprisingly, most recent platforms — Republican and Democratic — have put the economy first, right after the preamble. The exception was 2004, when both parties gave national security top billing. During the Cold War years, leading with security and defense issues was typical, however. These kinds of changes, which cross party boundaries, can give us a sense of society’s changing priorities.

They can also tell us about how a party might approach a broad issue like the economy. For Democrats, economic policy tends to include a combination of ideas that focus on the human effects of the economy. The party has shifted back and forth on which of these lead the economic agenda in the platform: in 1980 and 1988, it was economic justice. In most other years between 1984 and 2004, jobs and growth framed the economic planks. After the economic crash of 2008, security and saving the economy became the focus.

The space devoted to an issue varies widely as well. Democratic platforms around mid-20th century started to include longer and more extensive sections on civil rights. Agricultural issues often get a great deal of space; in 1960, the Democratic platform had three sections on agricultural policy. In 1988, the Republican platform had an extensive section on congressional reform, which included ideas such as subcommittee reform that informed the “Gingrich revolution” in the House of Representatives. Sometimes an issue is omitted entirely — the 2012 Democratic platform didn’t mention fracking — or an unexpected one is included, like the Republicans’ inclusion in this year’s draft platform of language that opposes cohabitation or supports gay conversion therapy.

The inclusion of those social issues suggests that while Trump has deviated from conventional party views on these issues, socially conservative groups are still highly influential in the party. The specificity of language may also tell us something about which groups have the most direct impact. For example, the 2016 Democratic platform lays out a series of very specific labor policies in its section on unions and protections for workers, showing the continuing influence of labor leaders on the party.

One of the big questions in political science is whether voters make choices based on prospective considerations – what they think different candidates or parties will do – or retrospective evaluations – how well they think a particular party or candidate has handled the responsibility they’ve already had.

Platforms can’t help us answer this question, but they do provide some clues about what parties expect or hope voters will do.

The 1964 Republican platform, for example, was retrospective, sharply criticizing the Kennedy-Johnson administration’s record on foreign policy, job creation and alleviating poverty, to name a few. The party’s 1984 and 1988 platforms were similarly retrospective, but in a positive way, showcasing specific accomplishments of the Reagan administration in the areas of job growth and regulatory reform. The reasoning behind this is not difficult to guess: If interest groups are so important to the nomination process and attentive to platforms, then it makes sense to highlight concrete accomplishments that appeal to them.

The 1964 comparison may be relevant this year. The party was divided that year and its nominee, Arizona Sen. Barry Goldwater, has been compared to Trump as a controversial and unpopular choice. Opposing the Johnson administration was perhaps the main thing the party could agree on. The party’s issue positions come through in the platform, but they are presented in terms of the Democrats’ failures to deliver results, perhaps indicating the party’s internal disagreement.

The balance between the incumbent’s record and plans for the future is important for the Democrats, too. Clinton needs to affirm the administration’s record enough to bolster her case for a third Democratic term, but she must also make the case for how her presidency would be different in policy terms.

Sometimes politicians do what platforms say, sometimes they don’t. But the way they say it — how platforms present parties’ past records and future plans — may give us a clue about what’s happening behind the scenes.