Abdul El-Sayed, an insurgent former public health official who harnessed Democratic frustration with the party establishment, narrowly defeated Rep. Haley Stevens in Michigan’s U.S. Senate primary, setting up a crucial test for progressives in a key battleground state.

El-Sayed will face Republican Mike Rogers, a former congressman, in November in a race that will help determine control of the Senate. His first challenge will be unifying Democratic factions after a bitter primary that offered divergent visions for a party desperate for a path back to power.

Stevens, who pledged her support for El-Sayed after conceding defeat, was backed by the Democratic establishment, including outgoing Sen. Gary Peters, whose retirement spurred a scramble to fill his seat. El-Sayed promised a more aggressive approach for confronting entrenched corporate interests and President Donald Trump, and declared his victory was nothing short of a political earthquake despite only scraping by Stevens.

His win, however slim, represents a significant shift for the Democratic Party; in 2018 he lost the gubernatorial primary to now-Gov. Gretchen Whitmer by 21 percentage points.

This is by no means the only article I've seen that mentions this. But what people seem to fail to remember is that at that time there had begun rumblings that if El-Sayed won the Democrat nomination there would be legal challenges to his candidacy. Michigan law requires one to have been a registered Michigan voter for 4 years prior to the election. While El-Sayed had registered to vote when he was 18 in Michigan, and never removed from the voting roles, he had registered and voted in New York like 3 years earlier when he was studying at Columbia.

Even the Republican Secretary of State indicated that she would not interfere with a party's nominating process and that if such a decision were necessary about any party's nominee it would only be taken up after their nomination.

After that came to light his poll numbers dropped significantly with Democrats fearing they would end up no one on the ballot. Personally, I doubt it would have gone that way, but people are scared.