OF THE checks on executive power in the constitution, perhaps the least needed is the amendment limiting presidents to two terms. Americans often invest sky-high hopes in those they send to the White House, choosing someone they believe will correct the flaws of a now-despised predecessor. After their first terms, presidents seeking re-election are frequently helped by the trappings of office. But after eight years the mood sours: Americans then long for change, and for someone younger, more competent or less mired in scandal.

The rules of presidential politics have never been applied to someone quite like Hillary Clinton. In the public eye for decades as a First Lady, senator, unsuccessful presidential candidate and then secretary of state, she is neither a serving world leader nor a fresh face. Mrs Clinton risks finding herself an unhappy hybrid: a candidate weighed down by all the disadvantages of incumbency, while enjoying rather few of the benefits.

The Iowa caucuses on February 1st—the first electoral contest of the 2016 presidential cycle—saw Mrs Clinton held to a virtual tie by her populist rival for the Democratic nomination, Senator Bernie Sanders of Vermont. Iowa is a state that holds horrid memories for Mrs Clinton: it is where Barack Obama beat her in 2008, halting what had seemed her almost regal progress to the Democratic nomination. This year, addressing supporters in Des Moines on caucus night, Mrs Clinton voiced “a big sigh of relief” after her razor-thin win, before rushing to catch a plane for New Hampshire, scene of the next nominating contest.

Iowa is not very like most of America. It is 90% white. Many of its Democrats are deep-dyed lefties huddled in college towns surrounded by conservative, God-and-guns farm country. Yet Iowa’s caucuses still offer lessons that will last, starting with the double-edged nature of Mrs Clinton’s strongest suit: her experience.

In 2008 Mrs Clinton was thumped by Mr Obama in the eastern county of Poweshiek, notably in the handsome Victorian college town of Grinnell. This time Poweshiek gave her almost half its votes. That improvement was hard won. Mrs Clinton and her husband both visited. Caucus day saw volunteers fanning out from a field office to knock on supporters’ doors. A poster in the office asked volunteers why they backed their heroine. At the top, someone had neatly written: “Because she is the best qualified non-incumbent to run since George Washington.”

David Leitson is the head of “Grinnellians for Hillary”, a campaign group at Grinnell College, a campus gripped by Bernie-mania. Ahead of the caucus he made three main arguments to classmates. First, that Mrs Clinton is ready to serve as president “on day one”. Second, that her plans to make college more affordable or regulate big banks overlap with the Sanders agenda but are more feasible. Lastly, that she has been “battle-tested” by years of ferocious conservative attacks—a trial that Mr Sanders would surely face as a nominee, as a self-described democratic socialist who wants to raise taxes, hugely expand the government and break up big banks. Unbidden, many Iowa Democrats describe a tussle between their heads, which tell them that pragmatic, centrist Mrs Clinton offers their best shot at beating the Republicans, and their hearts, which sing when Mr Sanders growls that America is a corrupt oligarchy. Mr Leitson sees no reason why electability cannot co-exist with excitement. Explaining his passion for the Clinton campaign, the undergraduate said: “My heart is in it because my head is in it.” He is a rarity, though: across Iowa, pollsters estimate, Mr Sanders won eight in ten caucus-goers under the age of 30. Mrs Clinton’s salvation was her support among older Iowans, who turned out in larger numbers than the young.

Gender specific: Hillary Clinton and female primary voters Not all Poweshiek Democrats found striking the balance between excitement and electability so easy. Rebecca Petig, a mother of four and an elected prosecutor, was surprised to find herself undecided hours before welcoming fellow party members to her own home, which was to serve as an official caucus precinct (unsure about the etiquette of feeding voters, she thought she might offer banana bread and coffee). Ms Petig sighed that Mr Sanders describes politics “as I’d like it to be, but realistically it’s not going to be that way”. She admires Mrs Clinton’s achievements, and expects her to become the Democratic nominee. But unexpectedly, she finds that she cannot hold Mrs Clinton up as a role model for her teenage daughter. The problem is Mrs Clinton’s “baggage”, involving years of alleged scandals and charges of dishonesty.

There isn’t anyone else, alas

Talk of baggage was rife at the Democratic caucus in Poweshiek’s 8th precinct, held in a Grinnell elementary school. Iowa Democrats caucus in public, showing their preferences by standing in corners of the room assigned to each candidate. Seeking to lure undecided voters to their corner, Sanders supporters did not cite the specific misdeeds of which Republicans accuse Mrs Clinton (most recently involving her alleged mishandling of top-secret government e-mails). Instead Sanders backers called Mrs Clinton part of a sleazy and unequal status quo, especially as the recipient of donations and speaking fees from billionaires and “banks that bankrupted the middle class”.

Mrs Clinton has “been around so long, you sort of get fatigued”, conceded Catherine Rod, a wavering voter at the caucus. She listened as a fellow Democrat urged her to cross to the Sanders corner so that “his ideas can get momentum”. But Ms Rod, a retired librarian, worried about the harm that defeat in Iowa might do to Mrs Clinton, fretting: “I don’t want to trash Hillary.”

Lots of Democrats feel similarly trapped. They have only one plausible general-election candidate, Mrs Clinton, and understand why lots of Americans are unexcited by her. Assuming that she survives her latest legal woes involving classified e-mails, Mrs Clinton will be the nominee. But Iowa was an early warning. A long, grinding slog awaits.