Sen. Ron Johnson (R-Wis.) is coming under fire from all sides for his investigations into the Obama administration and the Bidens.

Months into his probes, Johnson is facing increasing public pushback from Democrats, the Biden campaign and aligned outside groups who believe he is trying to undercut presumptive Democratic nominee Joe Biden and might inadvertently spread Russian disinformation in the process.

But he’s also taking criticism from high-profile conservatives who argue the probes are moving too slowly, while some fellow GOP senators appear worried about the appearance of the investigation just months before the election.

Johnson is now pushing back on some of his critics, accusing them of spreading false information about his investigations.

“This is exactly the same playbook they ran against President Trump,” Johnson said during an interview with “Justice & Drew,” a Minnesota-based radio show. “They’re doing the exact same thing to me and Sen. Grassley.”

Johnson is using his Homeland Security and Governmental Affairs Committee gavel to run two investigations, at times in coordination with Finance Committee Chairman Chuck Grassley (R-Iowa).

Both probes are viewed as controversial but inherently distinct: One involves the Obama-era State Department, Obama-era Ukraine policy including work done by former Vice President Joe Biden, his son Hunter Biden and any contact between the Obama administration and his associates or Burisma Holdings, where Hunter Biden was on the board.

The second is wide-ranging and broadly covers the transition process between the Obama and Trump administrations, but delves into everything from the FBI’s investigation into the Trump campaign and Russian election meddling and its offshoots to leaks from the early days of Trump’s presidency.

The tensions surrounding the probes are increasingly spilling over into the national spotlight as November draws near and the window for GOP investigations potentially comes to a close. Control of the Senate is up for grabs and political handicappers view Democrats as having momentum to win back the majority.

Conservative radio host Hugh Hewitt lacerated Johnson for not having subpoenaed former FBI Director James Comey, former CIA Director John Brennan or former FBI agent Peter Stzrok — three of more than 30 individuals Johnson got the power to subpoena in June.

"Are you aware that in the eyes of someone like me ... you're failing? Do you understand that the committee and Sen. Graham's committee on this issue are failing the American people? We don't have the answers," Hewitt said, referring to Sen. Lindsey Graham (R-S.C.) who is running his own investigation as chairman of the Judiciary Committee.

"I don't think, senator, you understand the depth to which people like me ... are absolutely disappointed in our senators," Hewitt continued. "We are going to lose this election if we lose it in the Senate, if we lose it in the Senate because you and Lindsey let them do this.”

But even as Johnson has faced scathing criticism for not moving fast enough, he tipped his hand to concerns from some of his GOP colleagues about the investigations.

“People have legitimate concerns. ... They wanted me to do everything I could to obtain the testimony and documents on a voluntary basis,” Johnson told Fox News. His office later clarified that no Republicans were currently blocking subpoenas.

Both Sens. Mitt Romney (R-Utah) and Rob Portman (R-Ohio) voiced concerns about the investigations in June, though they both granted Johnson broad subpoena authority as part of his probe of the transition between administrations and authorized a subpoena for Blue Star Strategies in the separate investigation involving Ukraine and the Bidens.

"I believe there are far more urgent priorities the committee should address,” Romney said at the time. “I continue to be concerned that this is politically motivated."

If Johnson wants additional subpoena powers he’ll need buy-in from the other seven Republicans on his committee, otherwise the vote would fail. He previously indicated he was considering subpoenas for former Obama officials, including former Deputy Secretary of State Antony Blinken, as part of his investigation that touches on the Bidens. But the Senate left for its August recess without Johnson pressing the issue, and he hinted that it could be challenging to get additional authority.

“I had a devil of a time just getting the subpoena authority that I got,” Johnson told Hewitt.

The GOP tensions come after Johnson previously said his committee had been “sidelined” when Senate Majority Leader Mitch McConnell (R-Ky.) tapped then-Intelligence Committee Chairman Richard Burr (R-N.C.) to look into Russia’s 2016 election meddling. Johnson added this week that McConnell had indicated Graham would take the lead on some issues.

As Johnson fends off GOP criticism, he’s facing a growing onslaught of attacks from Democrats, who are increasingly going public with their concerns that Johnson’s actions could have the effect of meddling in the 2020 election and allow for Russian misinformation so close to Election Day. Johnson previously told The Hill he was planning to release an interim report on the Ukraine-Biden piece around mid-September.

Feeding Democratic concerns, William Evanina, director of the National Counterintelligence and Security Center, said in a public statement that Russia was interfering in the 2020 election with an aim to “denigrate” Biden. He pointed specifically to pro-Russia Ukrainian parliamentarian Andriy Derkach as someone working to undermine Biden.

Americans “should know one other thing, that these hearings that Johnson and Graham are doing, some of it is now, now it’s public, is based on false Russian intelligence about Joe Biden,” said Senate Minority Leader Charles Schumer (D-N.Y.).

Derkach has publicly indicated that he’s shared information with Johnson. But the GOP senator has denied receiving anything and sought distance in a public letter.

“We have not taken, nor do we possess, the documents from Ukrainians that Democrats keep claiming,” Johnson wrote in an open 11-page letter explaining and defending his probes.

Johnson and Grassley have repeatedly said they did not set out to investigate the Bidens, that they began their probe before he announced his candidacy and that their actions are not driven by the fact the former vice president is now the presumptive Democratic nominee.

But Johnson has also increasingly gone public with his questions on Biden, including a 19-tweet thread on Friday with topics he believes the media should be raising with the former vice president.

Shortly before that, he helped fuel accusations that he’s using his gavel to help Trump when he said his investigation “would certainly” help the president’s reelection chances.

“The more that we expose ... the corruption of the transition process between Obama and Trump, the more we expose of the corruption within those agencies I would think would certainly help Donald Trump win reelection and certainly would be pretty good, I would say, evidence for not voting for Vice President Biden,” Johnson told “Justice & Drew.”

Biden’s campaign seized on Johnson’s comments, calling them the “definition of malfeasance,” and that it was “beyond time for him to end this embarrassing and deeply unethical charade once and for all.”

Multiple outside groups are asking for the Senate Ethics Committee to investigate whether Johnson is violating the chamber’s rules.

The group Democracy 21 is asking the Ethics Committee to determine if Russian disinformation is being laundered through the GOP investigation. Meanwhile, the Center for Media and Democracy and American Oversight sent a request asking the panel to look into whether Johnson is violating Senate rules, arguing he is using his committee perch to carry out campaign activity. A senior adviser for American Oversight used to work for Biden when he was a senator, though the group describes itself as nonpartisan.

“The Ethics Committee must investigate Senator Johnson's ongoing effort to use his official Senate position to improperly engage in partisan political activity and to accept and legitimize foreign efforts to influence an American election,” the two groups wrote.

Johnson’s office dismissed the request for an investigation into his actions.

“These are baseless political allegations made by longtime Democrat operatives,” a spokesperson for Johnson said. “Reputable members of the media should understand that and ignore this baseless complaint.”