Gehrke: For McAdams, marijuana proves effective — to give him a lead and probably a win in Utah’s 4th District

Maybe marijuana is a miracle drug.

It worked wonders for Ben McAdams’ campaign, which rode a late surge in support for the medical marijuana legalization to a narrow win over Republican Rep. Mia Love.

Now in a race as tight as this one, with a final margin of just 694 votes, everything matters — the Blue Wave effect, the increased turnout from vote-by-mail and same-day registration, Mitt Romney coattails (or lack thereof), all of it.

But the impact that the medical marijuana vote had on the outcome is hard to ignore.

Consider this: Utah had the largest increase in turnout since the last midterm of any state in the nation, according to data gathered by University of Florida political science professor Michael McDonald (numbers aren’t available for three states). Utah went from roughly 30 percent turnout in 2014 to more than 50 percent of eligible voters this year.

Nationally, voter turnout went up by 13 percent, so Utah’s surge far outpaced every other state, including those with strong Democratic bases and, presumably, much larger Blue Waves.

What’s more impressive is that other states near the top all had hotly contested, high-profile, multimillion-dollar races: the U.S. Senate race in Missouri, Senate and gubernatorial races in Nevada, a Senate race in Indiana, the gubernatorial race in Georgia.

How do we account for such an astonishing surge in Utah? OK, sure, Lt. Gov. Spencer Cox’s go-vote ads probably had something to do with it.

Maybe Mitt Romney on the ballot brought people out, but not the people he hoped would come out, especially in Salt Lake County. There, Romney finished just below 50 percent; he won 58 percent when he was on the ballot there in 2012.

And that goes to what is notable about Utah’s big spike. If you look at those other states that had voter turnout increases on par with Utah — Missouri, Indiana and Georgia — the Democrat lost to a Republican, meaning turnout increased on both sides. There were opposing waves crashing into one another.

In Utah, and more specifically, Salt Lake County, where the 4th District race was decided, we had an overwhelming surge, but it broke one way.

In Salt Lake County, more people voted for medical marijuana than Mitt Romney — and it wasn’t really close. Medical cannabis was 62,000 votes more popular than Mitt.

Let that sink in for a minute. Mittajuana.

In fact, as my colleague Bethany Rodgers noted, more people voted for or against Proposition 2 than voted in the Senate race that was at the top of the ticket — meaning people literally skipped the entire first page of their ballot, turned it over and voted for medical marijuana.

That’s why we saw Democrats winning in legislative races down-ticket; progressive propositions drawing strong margins in the most populous county; and other countywide races tilting blue.

A poll by The Salt Lake Tribune and Hinckley Institute of Politics before the election found that 30 percent of voters were motivated by the propositions, the vast majority of them by medical marijuana.

It’s true that the second strongest motivating factor was President Donald Trump — for or against him, but in the 4th District, mostly against.

So, absolutely, there was some level of Blue Wave. Utah would probably have seen bigger Democratic turnout this election whether or not Proposition 2 was on the ballot.

But with medical marijuana in play, we saw a “Green Wave” that far and away overwhelmed anything in its path.

And the wave crested right before the election. According to Salt Lake County, 22,000 people registered to vote in the final week. More than 8,000 registered and voted on Election Day. And, in Salt Lake County, more than 80 percent voted for Proposition 2. And 64 percent voted for McAdams — a remarkable 10 full points higher than he had seen to that point in Salt Lake County.

It was the decisive blow in a hard-fought campaign.

All of that raises some questions going forward. Will those young, progressive people stay involved? Will they vote next time? Can Spencer Cox produce an ad compelling enough to keep them interested?

If they stay engaged, it could change the political calculus in Utah long-term. If they don’t, we’ll slump back to mediocre turnout numbers, McAdams could struggle in his re-election bid in 2020, and Republicans will restore their grip on Utah politics.

For 2018, though, marijuana was a miracle drug.