LANSING — The state has tough days ahead in its fight against the coronavirus pandemic, but a return to normalcy is "on the horizon," Gov. Gretchen Whitmer said at a news conference Monday.

Whitmer rejected a Monday tweet from Republican President Donald Trump, who said it will be up to him — not the nation's governors — when the economy reopens.

The economy "doesn't get opened up via Twitter," Whitmer said. "It gets opened up at the state level."

The 10th Amendment to the U.S. Constitution reserves to the states those government powers not specifically assigned to the federal government. Those state powers include ones related to policing and regulating safety and public welfare — all associated with "stay-at-home" orders issued by many governors, including Whitmer, that have shut down most businesses.

Trump said in his tweet that decisions about restarting the economy are up to him and the federal government, though he said he planned to work closely with governors in making those decisions.

Whitmer said the factors she will be looking at will be a sustained reduction in infection, an enhanced ability to test and trace, sufficient hospital capacity to deal with a resurgence, and workplace protocols to keep employees safe.

Whitmer, responding to criticism of her extended and expanded stay-at-home order issued last Thursday, said nobody wants to start reopening the economy more than she does.

Republican legislative leaders and some business leaders have said Whitmer's measures are too restrictive and say they should be focused more on what work can be done safely, rather than what work is considered essential. They have also called for a more regional approach to the restrictions, with greater flexibility allowed in parts of the state less hard-hit by the virus.

"Every day we are writing the plan so we can re-engage safely, at the appropriate time," Whitmer said.

However, "not one of us wants to go through this again," and that's why "we have a few tough days ahead of us."

Whitmer, who has previously said the state could see its peak in cases in late April or early May, did not say when she expects the state can start to move toward normalcy. Her present stay home order is scheduled to be lifted May 1.

More:Michigan's stay-at-home order: We answer 20 frequently asked questions

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Whitmer said it is clear the state's social distancing efforts are working and she is cautiously optimistic the state's projected curve for COVID-19 cases is beginning to flatten. But at this point, she said her main focus must be saving lives, not saving the economy.

She said she has not taken any actions lightly and she understands the economic hardship and anxiety some of those measures have created.

"It's OK to be frustrated, it's OK to be angry," Whitmer said. "If it makes you feel better to direct it at me, that's OK, too. I have thick skin."

But with a demonstration in opposition to her stay home order planned for the Capitol at noon Wednesday, Whitmer urged anyone who protests to do so safely, so they don't further spread the virus or put police officers or other first responders at risk.

Whitmer said she understands some questioning why they can buy lottery tickets, for example, but not seeds for their gardens. "I get it," she said, though she did not announce any plans to rectify those apparent inconsistencies.

Responding to criticism of her deeming nurseries and garden shops as nonessential, Whitmer said she knows there are many avid gardeners in the state but that the peak planting season is weeks away, especially with unseasonably cool weather. She said the state will do all it can to make sure owners of nurseries and related industries have access to small business loans and other financial aid.

She said she expects Michigan's economy will be reopened in phases, but right now it does not make sense to allow some parts of the economy, or some parts of the state, to reopen.

"Just because you live in a region with (only) a few cases doesn't mean it can't spread rapidly," she said.

And hospitals in those rural areas with relatively few cases are not equipped to handle a surge if one occurs, she said.

Doug Rothwell, president and CEO of Business Leaders for Michigan, noted that Whitmer has said she will call on a group of Michigan’s health care, research university, business and labor leaders for advice on when and how to restart the economy.

“We’re anxious like most are to get back to 'normal,' but we’ll get there faster if we do it the right way," Rothwell said in a news release. "The governor understands this and we will do our part to help her write the right playbook.”

Contact Paul Egan: 517-372-8660 or pegan@freepress.com. Follow him on Twitter @paulegan4. Read more on Michigan politics and sign up for our elections newsletter.