WASHINGTON (AP) — Joe Biden and Donald Trump are marching toward their respective presidential nominations. But Michigan’s primary on Tuesday could reveal significant political perils for both of them. Trump faces a bloc of stubbornly persistent GOP voters who favor his lone remaining rival, former U.N. Ambassador Nikki Haley. Biden is confronting an energized movement of disillusioned voters upset with his handling of the war in Gaza. Michigan is the last major primary state before Super Tuesday and a critical swing state in November’s general election. Even if Biden and Trump post dominant victories on Tuesday, both campaigns will be looking at the margins for signs of weakness.