FLINT, US - A combative President Barack Obama has visited crisis-hit Flint, Michigan, where he conspicuously sipped filtered water to prove it was potable and attacked “corrosive” Republican attitudes toward “big government.”

More than 8,000 children are believed to have consumed lead-contaminated water in the hardscrabble northern city, which has become a focus of the 2016 election campaign.

Republican and Democratic presidential candidates have used the crisis to trade barbs about the failings, size and role of local and federal governments. The town has a Democratic mayor and the state governor is a Republican.

Obama wasted no time in offering his take, linking the crisis to “a corrosive attitude that exists in our politics.”

“It’s a mind-set that believes that less government is the highest good, no matter what.” “This was a man-made disaster. This was avoidable, this was preventable,” he said, pointing to a “pipeline of neglect.”

The contamination began after a decision in 2014 to shift Flint’s water source from the Detroit River to the Flint River as part of cost-cutting measures ordered by state Governor Rick Snyder, a Republican who has consistently resisted calls to resign. Experts believe the chemical-laced Flint River water corroded lead pipes, allowing large amounts of the poisonous element to leach into the city’s water.

The state attorney general has filed criminal charges against a city official and two state regulators for allegedly falsifying tests and tampering with evidence.

Before Obama took to the stage, Snyder made brief remarks but was roundly booed by the 1,000 strong crowd. While Obama set out to make a political point, his address was also part public service announcement.

He used a coughing fit to show that tap water is safe to drink as long as it is filtered. “I really did need a glass of water. This is not a stunt,” he said.

Earlier, during a meeting with a group of government officials responding to the crisis, Obama cautioned residents about drinking unfiltered water and the scale of the problem the rust belt city faces in replacing lead-tainted pipes.

“It might take a year,” he said. “It might take two years. It might take more.”

Located in the heart of America’s declining industrial rust belt, Flint has come to represent the crossroads of many of the issues dominating the 2016 election cycle - foreign trade, environmental standards, the economy and the gap between rich and poor.

Democratic candidates Hillary Clinton and Bernie Sanders even held a presidential debate in Flint ahead of the Michigan primary in March.

Sanders’s strident message about the need to address income inequality narrowly won the day in the Democratic primary. Now the state is set to become a battleground in the general election, too.

Donald Trump’s populist message targeting disaffected white voters also propelled the Republican presidential frontrunner to win his party’s Michigan primary.