About 7 million fewer Americans have health insurance today than did four years ago, a new survey has found, the highest uninsured rate since 2014. The results come after sustained Republican attacks on government-backed health schemes, including the Affordable Care Act, better known as Obamacare.

The survey’s findings come as the public is increasingly interested in government-run health programs.

The United States is the only large, highly developed country that lacks universal health coverage. At the same time, healthcare costs in the US are the highest in the world, and can be financially catastrophic.

This fact has perplexed international health advocates, such as the former UN secretary general Ban Ki Moon, who told the Guardian last fall the American health system is “morally wrong”.

The new figures come from a survey, conducted by Gallup, which since 2008 has asked roughly 28,000 people a quarter “Do you have health insurance?”. In 2018, pollsters found 13.7% of Americans lacked health insurance, the highest levels since 2014. The change represents a net increase of 7 million uninsured individuals.

Comparably in 2014, the number of people without insurance was decreasing because Obamacare was going into effect. At its peak, just after Obamacare was passed but before it went into effect, nearly one-in-five Americans lacked health insurance.

Uninsured rates were at their lowest around the time of Donald Trump’s election in 2016 (around 10.6%), Gallup reported, and began to rise after a series of sustained Republican attacks on the law.

Republicans in conservative states introduced work requirements to Medicaid, with the approval of the Trump administration. As well, the administration cut the budget for government workers who help Americans sign up for insurance. Known as “navigators”, the administration cut their budget from $63m in 2016 to $10m in 2018. In a Republican plan to cut taxes (predominantly for the wealthy and corporations), they also eliminated a tax penalty for Americans living without health insurance.

Attacks on the ACA crescendoed this fall, when a Texas appeals court judge ruled major portions of the law were unconstitutional, following Republicans’ elimination of the tax penalty. The suit was brought by Republican state attorneys general.

Another poll released this week from the Kaiser Family Foundation showed how Americans feel about proposals to expand government-run health programs. While a majority (56%) supported single-payer coverage (akin to the UK’s NHS], called Medicare-for-All, large majorities on both sides supported “buy-ins” to existing government-run health plans.

In those scenarios, people who do not get health insurance from an employer could buy health insurance through either Medicaid or Medicare. Two-thirds of Republicans and wide margins of Democrats and independents supported the proposals.