When Donald Trump’s Federal Communications Commission voted December 14 to eliminate net neutrality, Massachusetts Senator Ed Markey announced that he would lead a Senate fight to overturn the FCC’s move and restore what advocates correctly describe as “the First Amendment of the Internet.”

“We will fight the FCC’s decisions in the courts, and we will fight it in the halls of Congress,” declared Markey, who moved immediately to introduce a Congressional Review Act (CRA) resolution to undo the FCC’s “historic mistake.”

“With this CRA,” the Democrat who has long been a key congressional leader on communications issues explained, “Congress can correct the Commission’s misguided and partisan decision and keep the internet in the hands of the people, not big corporations.”

Markey made it clear in December that he intended to force the issue. But to do this, he needed at least 30 senators to sign on in support of his resolution. That’s the number of Senate votes that is required to discharge a resolution and move it to the Senate floor for a vote. That may have sounded like a tall order. But with the Monday announcement by Missouri Democrat Claire McCaskill that she would co-sponsor the measure, 30 senators were formally on board.

Then something remarkable happened.

McCaskill’s decision opened the floodgates, as almost a dozen additional senators rushed to sign on.

By Tuesday morning, the list of supporters included 40 Democrats and independents who caucus with the Democrats. Then a Republican, Maine Senator Susan Collins, announced that she would back the resolution. The move by Collins created a new dynamic.

Now, says Mark Stanley of the group Demand Progress, “If all Democrats support Senator Markey’s resolution to restore net neutrality—which already has over 40 cosponsors and is guaranteed a floor vote—then only one more Republican is needed to pass the Senate.”

This week’s developments have upped the ante considerably. So much so that Hawaii Senator Brian Schatz says:

After I saw millions of people fight for net neutrality [l]ast year I thought I understood the passion behind it. But the momentum for this legislation to save net neutrality has surpassed my most optimistic expectations. We can win this Senate vote.

Seriously? Yes, seriously.

When the FCC delivers the final rules to Congress, Markey’s CRA will provide a focus for intensive lobbying of senators of both parties and every idealogical tendency to reverse the damage done by the FCC.

The Senate is just one battleground in a multifaceted legislative, legal, and popular struggle to restore net neutrality. But it is a high-profile battleground where the issue can be put in perspective for 2018 voters. Senate Democrats have made it clear that they will make the fight for the future of the Internet an issue in races featuring Republicans who side with the FCC. “Millennials were born into a world with a free and open internet. It’s as integral to their daily lives as a morning cup of coffee,” says Senate Democratic leader Chuck Schumer. “So when the administration rips it from their hands and hands it over to the big ISPs on a silver platter, millennials will know that Republicans were responsible—you can bet Democrats are going to make sure of that.”

Schumer is right that net neutrality is an issue that could mobilize young voters to head for the polls and cast Democratic ballots.

That threat puts pressure on Republicans who are up for reelection in 2018, and on the handful of GOP senators who have sought to identify themselves as responsible legislators. The net-neutrality resolution provides a relatively easy—and popular—way to signal that they are not simply extensions of the Trump administration.

As Markey says:

Our Republican colleagues have a choice—be on the right side of history and stand with the American people who support net neutrality, or hold hands with the big cable and broadband companies who only want to supercharge their profits at the expense of consumers and our economy.

The stakes are high. Some of the most powerful corporate lobbyists in Washington will work with McConnell and his allies to block Markey’s resolution. But advocates are preparing to pressure Republicans and wavering Democrats to do right by the future. And they have the vast majority of Americans on their side.

Referencing a December University of Maryland poll that shows 75 percent of Republicans (along with 89 percent of Democrats and 86 percent of independents) support net neutrality, Free Press Action Fund policy director Matt Wood says: “Supporting Net Neutrality should be a no-brainer for members of Congress, whose constituents from across the political spectrum are united in their opposition to the Trump FCC’s attack on the open internet. More and more lawmakers are recognizing this truth, helped along by the forceful outcry from the people they represent.”