Four states states will see gun control initiatives on the ballot this year: Maine, Nevada, California and Washington. Three of the four pieces of proposed legislation focus on expanding background checks. “Question 3” in Maine and “Question 1” in Nevada will ask voters whether or not background checks should be required for all firearm sales and transfers, including private sales (defined as sales between parties who are not licensed dealers). In California, Proposition 63 is calling for background checks when purchasing ammunition and magazines.

Gun control groups and advocates are doing everything in their power to get voters to check “yes” on November 8, and have thrown millions of dollars at promoting the these ballot initiatives.

According to Reuters, the gun control group Everytown for Gun Safety, founded by former New York City Mayor Michael Bloomberg, “has been leading the charge, throwing its financial weight behind three of the four measures. The organization plans to spend $25 million nationwide on the issue.”

Bloomberg has personally thrown almost $10 million toward the initiative in Nevada, and the gun control group Nevadans for Background Checks has collected a total of $14.3 million for the effort.

In Maine, Bloomberg’s PAC, along with the Mainers for Responsible Gun Ownership Fund, has collected $5.3 million.

Unfortunately, it looks like the pro-gun control efforts may be paying off. Polls show that these new measures will likely pass in all four states on November 8. In Maine, more than 60 percent support the initiative, while Nevada currently polls at fifty-eight percent in support.

If these measures pass, half of the U.S. population would be living in states with expanded background checks.

Their passage would also represent a huge win for gun control groups who failed to instill federal change after the Sandy Hook Shooting in in 2012. The bipartisan Manchin-Toomey “gun control compromise,” which aimed to expand background checks in all 50 states, was shot down by the U.S. Senate in 2013.

Gun control groups like Everytown are now taking a similar approach as did proponents of same-sex marriage—winning over state legislature. They are focusing on local victories, hoping to eventually influence federal law if enough states are turned.