Guns, taxes and GOP claims are getting the most attention from PolitiFact Wisconsin viewers.
Tom Kertscher with the Milwaukee Journal Sentinel talked about the top Four at Four clicked stories in May.
#4. Kevin Nicholson: Conservative mega-donor Richard Uihlein is a Wisconsin resident.
Nicholson is the other Republican hoping to win the GOP nomination to challenge Baldwin. He released a list of Wisconsin supporters of his campaign that included "Dick and Liz Uihlein (Minocqua)."
The Uihleins are major business owners in Pleasant Prairie and own property in Manitowish Waters, both in Wisconsin. But Richard E. Uihlein is frequently referred to in the media as an Illinois businessman and he is a registered voter of Illinois. So is his wife, Elizabeth A. Uihlein.
PolitiFact Wisconsin rating: False.
#3. Jeff Greenfield: "In the rest of the world, there have been 18 school shootings in the last twenty years. In the U.S., there have been 18 school shootings since January 1."
This February 2018 fact check on Greenfield, a broadcast commentator and University of Wisconsin graduate, drew new attention after the May 2018 school shooting in Santa Fe, Texas.
By one count widely cited in the news media, there had been 18 incidents in which shots were fired inside or outside of a school or university building in the United States at the time of the school shooting in Parkland, Fla. in February 2018.
But only three involved a mass shooting. And the count included two suicides, three accidental shootings and nine incidents in which there were no fatalities or injuries.
PolitiFact Wisconsin rating: Mostly False
#2 Leah Vukmir: Tammy Baldwin is "more worried about the mastermind of 9/11" than supporting CIA director nominee Gina Haspel."
Vukmir is one of two Republicans running in 2018 for the U.S. Senate seat held by Baldwin, a Democrat.
She provided no information to back up an extreme claim that Baldwin has serious concern for Khalid Sheikh Mohammed and that it was motivating her not to support Haspel.
PolitiFact Wisconsin rating: Pants on Fire.
#1. Paul Ryan: On the tax reform law, Democratic leaders "are promising to take it all away."
As the Republican House speaker said, Democratic leaders in Congress have been harshly critical of the law, adopted in December 2017, and have talked about the need to repeal or at least review most of it.
But the tax reform law also provides tax benefits to the middle class, which the Democratic leaders have indicated they want to keep.
PolitiFact Wisconsin rating: Half True.