GRAND RAPIDS, Mich. — Donald Trump plunged into his final-week sprint to Election Day decidedly on his terms: unleashing a harsh new attack against Democrat Hillary Clinton in Michigan, a state that hasn’t favored a Republican for president in nearly three decades.

His message Monday was welcomed by supporters, but his location frustrated anxious Republicans who fear their nominee is riding his unorthodox political playbook too long – even as Clinton’s developing email problems offer new political opportunity.

“Her election would mire our government and our country in a constitutional crisis that we cannot afford,” Trump declared in Grand Rapids, pointing to the FBI’s renewed examination of Clinton’s email practices as evidence the former secretary of state might face a criminal trial as president.

National polls show a tightening race. But with more than 23 million ballots already cast through early voting, it’s unclear whether Trump has the time or capacity to dramatically improve his standing over the next week in states like Michigan, where few political veterans in either party expect a Republican victory on Nov. 8.

Clinton, defending herself from the new FBI examination, focused Monday on battleground Ohio, a state Trump’s team concedes he must win.

“There is no case here,” Clinton insisted. “Most people have decided a long time ago what they think about all this.”

Later in the day, Clinton campaign manager Robby Mook decried what he called a “blatant double standard” following a CNBC report that FBI Director James Comey opposed releasing details about possible Russian interference in the U.S. election because it was too close to Election Day. Comey issued a letter to congressional leaders on Friday about the FBI’s renewed interest in Clinton’s email.

The AP has not confirmed the CNBC report, and the FBI declined to comment Monday.

In another development Monday, CNN said it was “completely uncomfortable” to learn through WikiLeaks that former commentator Donna Brazile had contacted the Clinton campaign ahead of time about a question that would be posed during a presidential primary town hall last March in Flint, Michigan.

CNN announced Monday that it had accepted Brazile’s resignation as a contributor two weeks ago. Her deal had been suspended in July when she became interim head of the Democratic National Committee.

Amid the attacks and counterattacks, the race for the White House remains at its core a test of a simple question: Will the conventional rules of modern-day campaigns apply to a 2016 election that has been anything but conventional?

For much of the year, Clinton has pounded the airwaves with advertising, assembled an large voter data file and constructed a nationwide political organization that dwarfs her opponent’s.

The Democratic nominee and her allies in a dozen battleground states have more than 4,800 people knocking on doors, making phone calls and working to support her candidacy. Clinton’s numbers, as reported in recent campaign filings, tripled those of Trump and the national and state Republican parties.

Over the past year, Trump has largely ignored the key components of recent winning campaigns, depending instead on massive rallies and free media coverage to drive his outsider candidacy. This week, he’s devoting his most valuable resource – his time – to Michigan, New Mexico and Wisconsin, the states where polls suggest he’s trailing Clinton by significant margins.

Adding to Trump’s challenge: Millions have already voted across 37 states, including critical ones such as Florida, Nevada and Colorado, where one-third of the expected ballots already have been cast.

The breakdown of those voters by party affiliation, race and other factors point to an advantage for Clinton.