DETROIT — Governor Rick Snyder of Michigan hired a law firm using $800,000 in taxpayer money to help his administration navigate a throng of civil and criminal investigations. Both candidates for the Democratic presidential nomination have called for him to resign.

On Thursday he faces a grilling by a congressional committee in Washington. And as voters went to the polls on the state primary election last Tuesday, a group led by a Detroit pastor began an effort to recall him in a statewide referendum, a repeat of the movement that in 2012 targeted a fellow Republican, Governor Scott Walker of Wisconsin.

For a man who swept into office in 2010 by touting his résumé as a no-nonsense accountant and businessman who was above politics, Snyder now finds himself in the middle of the kind of bitter partisan warfare that he has long disdained.

Many Michigan voters now blame him for how he handled two of the state’s biggest debacles, the tainted water crisis in Flint and the tattered Detroit public schools.

Though he is subject to term limits and cannot run for reelection in 2018, Snyder is now under threat of a recall, an effort that began in full force Tuesday.

At school and library polling stations in Detroit, volunteers handed out literature, recruited help, and urged voters to support the petition drive when signature collection begins later this month.

“He’s shown us that he’s just a businessman, not a governor,’’ said Wanda Jan Hill, 65, a Democrat and retired city employee, as she distributed leaflets outside a community center on the east side of Detroit. “He knew what was happening in Flint and he did nothing. Where is the compassion?’’

E-mails showed that a series of government errors surrounding Flint’s switch to a new water source were compounded by a lack of response over many months, despite growing evidence that the water was unsafe with high levels of lead.

Snyder, 57, has repeatedly apologized for his administration’s slow response, saying it was a failure on every level of government, and has voluntarily released thousands of pages of e-mails in an effort at transparency over the matter.

On Friday, he expanded the investigations into the crisis, calling on the state’s auditor general and the inspector general of the state Department of Health and Human Services to look into the health agency’s actions.

But recently Snyder has also begun to fight back. During a Democratic debate on March 6 in Flint, Hillary Clinton, courting the state’s liberal voters, made a sharp call for him to step down, echoing the sentiments of her opponent, Senator Bernie Sanders, as well as those of many residents and lawmakers.

While the Democrats were still on stage, Snyder fired off posts on Twitter defending his record, saying that political candidates “will not be staying to help solve the crisis, but I am committed to the people of Flint.’’ He also posted online a bullet-point chart that attacked Clinton and laid out “fact v. fiction’’ on Flint.

Snyder declined a request for an interview. But a spokesman, Ari Adler, reiterated Snyder’s pledge to stay and fix the Flint crisis, despite the recall effort circling him.

“Governor Snyder is fully committed to staying in office and putting every effort he can into restoring clean water for the people of Flint and correcting the mistakes in the government bureaucracy that caused the crisis in the first place,’’ Adler said.

“After the political rhetoric from presidential candidates has blown into another state, Governor Snyder will still be here in Michigan, and specifically in Flint, working hand in hand with city and state leaders to move Flint forward,’’ Adler said.

Some prominent members of his party have rallied to his defense: Senator Marco Rubio of Florida said in a Republican debate in Detroit this month that Democrats were unfairly politicizing the issue.

Snyder’s opponents have said that the governor’s political crisis is one of his own making, the result of a disconnected management style and lack of knowledge of the workings of government.

“I like the guy,’’ said Reginald Williams, a substitute teacher, as he left a polling place in Farmington Hills, Mich., on Tuesday. “But the way he’s handled Flint is sloppy. You see people holding up bottles of gold water, you check it out. The fact that he didn’t do that shows his level of neglect.’’

Snyder was elected in a robust year for Republicans, when they took control of statehouses and governor’s offices across the country two years after President Obama’s election.

Michigan was particularly hit hard at the time, reeling from depopulation, stagnant economic growth and the loss of manufacturing jobs. He emphasized his business skills during his campaign.

The political pressure on Snyder has been building. Investigations have been launched by the FBI and the Michigan attorney general.

The state Board of Canvassers has so far approved two petitions to recall Snyder; the groups may work together to collect signatures. If successful in gathering 790,000 signatures of registered voters in 60 days, the issue could go to a vote in November.

The Detroit public schools have been under state appointed emergency managers for years and officials have warned that the district could be insolvent within weeks.