Democratic Sens. Charles E. Schumer (N.Y.), center, and Edward J. Markey (Mass.), far right, are prominent opponents of the GOP-led FCC's policy on net neutrality. (Olivier Douliery/Getty Images, File)

Internet activists and tech companies are kicking off a series of protests Wednesday to draw attention to net neutrality once again. What's at stake now is a key piece of legislation on the hot-button issue that lawmakers on Wednesday will seek to bring to the Senate floor. When the GOP-led Federal Communications Commission voted last year to repeal the agency's net neutrality rules for Internet providers, many Democratic policymakers vowed to oppose the decision, arguing that the FCC's policy change could benefit ISPs at the expense of regular Internet users. Now that effort faces a critical test, as the expected legislation is aimed at restoring the net neutrality rules. Here's a look at the issue.

What is this legislation all about?

The legislation is a resolution of disapproval proposed by a number of mostly Democratic lawmakers, such as Sens. Charles E. Schumer (N.Y.) and Edward J. Markey (Mass.). It has one Republican co-sponsor, Sen. Susan Collins of Maine.

The senators are pushing forward the resolution under what's known as the Congressional Review Act, a law that permits Congress to review — and reject — administrative decisions by federal agencies. In this case, the resolution (or CRA, for short) would overturn the FCC's repeal vote, effectively bringing back the net neutrality rules and making it harder for the agency to attempt to repeal them again.

What's net neutrality about, again?

Net neutrality is the idea that ISPs shouldn't block or slow down websites and apps as their content makes its way to your screen. It also holds that Internet providers shouldn't be allowed to offer faster delivery to websites and apps in exchange for extra fees, out of fear that big companies could use their wealth to buy preferential treatment and squeeze out competition.

A Democratic-led FCC voted in 2015 to turn those principles into a set of codified regulations. The following year, a federal court upheld the rules against Internet providers who argued that the regulations were too restrictive and harmed their ability to make more money and invest in next-generation infrastructure.

The rules came under fire again, however, when the Republicans retook the FCC as a result of the 2016 election. Last year, in a 3-2 vote led by Chairman Ajit Pai, the FCC moved to roll back the net neutrality rules.

What does that mean?

In addition to stripping away the specific net neutrality rules, the FCC proposal went further — saying that the agency doesn't have the legal authority that it had used to regulate Internet providers with the 2015 rules.

The FCC vote effectively changed the scope of what the federal government considers a net neutrality violation and placed much of the responsibility for enforcing those violations in the hands of another agency, the Federal Trade Commission.

For example, under the FCC's old approach, Internet providers are prohibited from blocking or slowing down Web services, period. Under the new approach, blocking and “throttling” are permitted; the ISP simply needs to disclose to consumers that that's the provider's policy. The FTC may still sue carriers for blocking or throttling, but generally only in cases where the ISP's practices conflict with what it may have promised in marketing, fine print or other public materials.

How does the Senate vote come into play?

The Senate effort to overrule the FCC's policy change is the first of several legislative hurdles. To advance, the resolution needs the approval of a simple majority. In this case that means 50 votes, because of Sen. John McCain's (R-Ariz.) medical absence. Supporters of the CRA have already said that they have the necessary 50 votes to advance it. Although the lawmakers are filing a discharge petition on Wednesday with the aim of forcing a floor vote, it may take up to a few weeks for the vote to take place, depending on the chamber’s schedule, according to a Democratic aide, speaking on condition of anonymity to discuss private negotiations.

Barring any surprises, a successful vote in the Senate will send the resolution to the House. If it succeeds there, it will head to President Trump's desk for signing.

How certain is that outcome?

It's not clear whether House leadership intends to bring the resolution to a vote. If it doesn't come up, then the CRA could end up dying there. AshLee Strong, a spokeswoman for House Speaker Paul D. Ryan (R-Wis.), referred questions to House Majority Leader Kevin McCarthy (R-Calif.). A spokesman for McCarthy, Matthew Sparks, declined to comment on when or whether the House could take up the CRA, saying that the House is dedicated to working on a separate net neutrality bill “to permanently address this issue.”

Even if the resolution passes the House, Trump — whose administration applauded the FCC for repealing the net neutrality rules — is not expected to sign the measure.

So what's the point?

Although the legislative gambit by Democrats may prove less than fruitful, many of them say it's still worth pursuing because it's all about this year's midterm elections. Companies such as Reddit, Etsy, Tumblr and Pornhub have said they will participate in Wednesday's protest, in an effort to galvanize Americans on the issue. (Internet activists, meanwhile, say the rallies are simply aimed at pressuring Congress to vote their way on the CRA, not to highlight the midterms.)

The location technology company Foursquare said Tuesday it intends to run a series of ads this week on its platform to pressure U.S. lawmakers from five states: Arkansas, Colorado, Florida, Louisiana and Nevada. The state-specific custom ads, which will appear to viewers like a slow-loading website, are being targeted to 26 million Americans.

"These are people who live in the five states where, based on insight from senators who are advocates on the net neutrality vote upcoming, swing senators may be more willing to side for a free and open Internet," Foursquare chief executive Jeff Glueck said.

Whether the protest and the CRA will drive voters to the polls in November is unclear. But supporters of the net neutrality rules believe it could help bolster their gains in what some predict could be a wave election for Democrats.