President Donald Trump speaks to the media prior to departing on Marine One from the South Lawn of the White House in Washington, DC, March 28, 2019, as he travels to Michigan to hold a campaign rally before spending the weekend in Florida.

President Donald Trump heads to swing state Michigan on Thursday to buoy his 2020 re-election bid, basking in perhaps the best political news of his presidency but facing fresh risk after reopening his fight to scrap Obamacare.

The president has gloated at political rivals and news media outlets ever since Attorney General William Barr released a summary Sunday of special counsel Robert Mueller's nearly two-year probe into Russian efforts to influence the 2016 election.

The Justice Department concluded not only that the Trump campaign was not guilty of colluding with Russia but also that Mueller did not find sufficient evidence to charge Trump with obstructing the investigation. Mueller himself did not draw a conclusion on obstruction and, the summary noted, the report did not "exonerate" Trump.

The Trump administration quickly trampled on the good feelings. The Justice Department said Monday that it agrees with a federal judge's determination that the Affordable Care Act is unconstitutional — a move that reportedly divided the White House and confused congressional GOP leaders. Members of both major parties largely see the GOP's attempts to repeal the health-care law as the main reason Democrats flipped 40 House seats and control of the chamber in November's midterm elections.

For better or worse, the president will likely drill into both themes at his Grand Rapids, Michigan, rally on Thursday night. Michigan helped to send Trump to the White House in 2016, handing him a razor-thin, roughly 12,000-vote win over Democrat Hillary Clinton. Before Trump's election, Michigan had last voted for a Republican presidential candidate in 1988.

But Trump had a net -15 approval rating in Michigan in February, according to Morning Consult. He had a +8 approval rating in the state in January 2017, just before he took office.

Trump won key Rust Belt states Michigan, Wisconsin and Pennsylvania — which delivered enough electoral votes to swing the election on their own — by pledging to revive their manufacturing and auto industries. But all three states drifted away from the president in last year's midterm elections, in no small part because of the GOP attempts to repeal Obamacare.

A strong economy gives Trump solid footing in his bid for re-election, despite a relatively low approval rating. However, a new push to toss out Obamacare without a viable replacement threatens to put the focus back on one of Trump's more damaging policy plans and overshadow the good news around the Mueller report.