A whistleblower's complaint and a tight timeline are making it increasingly unlikely that the Senate will confirm Chad Wolf as secretary of the Department of Homeland Security before the election.

Donald Trump formally sent the nomination late Thursday to the Senate after announcing his intention to appoint Wolf in a tweet last month. But Republican senators, who are fighting to keep their majority in November, appear in no rush to launch a heated confirmation that will force uncomfortable questions about whether agency actions were driven by Trump's political agenda.

The Senate's Homeland Security and Government Affairs Committee, headed by Republican Sen. Ron Johnson of Wisconsin, may still pursue a hearing to consider Wolf's nomination in the weeks ahead.

But the full Senate is unlikely to hold a confirmation vote before the election, said two Republican aides granted anonymity to discuss private deliberations. Senators could recess by the end of the month.

On Friday, Rep. Adam Schiff (D-CA), the chair of the House Intelligence Committee, announced his panel was expanding its probe into politicization at DHS following the whistleblower's complaints over the department's handling of intelligence information on election interference by the Russians, the threat posed by white supremacists and other matters.

Schiff wrote to DHS officials that based on the new information the committee's investigation will now encompass "a wider range of reported abuses, deficiencies, and problems, including allegations of improper politicization of intelligence and political interference."

It was already going to be hard to secure a confirmation vote before the Senate heads into an October recess even before the new allegations that Wolf and other DHS officials sought to influence intelligence.

Trump said it will be up to Wolf to answer questions raised in the complaint from Brian Murphy, who said he was demoted from his DHS intelligence post after a series of clashes with agency leaders over reports on threats to the homeland.

Trump told reporters Thursday that he hadn't seen the whistleblower complaint. "But ask Chad Wolf," he said before heading to a campaign rally in Michigan. "He's the one that would know something about it."

DHS spokesman Alexei Woltornist has said the agency denies there is "any truth," to the complaint Murphy made to the agency's Office of Inspector General, which provided additional ammunition to Wolf critics who were already accusing him of politicizing the agency by deploying federal forces against protesters in Portland, Oregon, and elsewhere without support from local officials.

Trump appointed Wolf acting secretary in November 2019, following the resignation of Kevin McAleenan, the acting secretary who took over following the resignation of Secretary Kirstjen Nielsen.

Wolf had been a chief of staff to Nielsen and an undersecretary in the agency as well as an official at the Transportation Security Administration, a component of DHS. He has also worked as a lobbyist.

Trump has said he likes the "flexibility" of having senior officials in an acting status despite criticism that it keeps people from long-term planning that would give an agency more stability.

Trump nominated Wolf, who has been in the temporary status for more than 300 days, after the Government Accountability Office determined that, neither Wolf nor his deputy, Ken Cuccinelli, were legally eligible to run DHS because of a violation of the rules of succession in federal agencies. That finding has put policy changes under their tenure, especially related to immigration, in potential jeopardy amid legal challenges.

The nomination also came after Wolf became closely identified with Trump's response to the civil unrest that followed the police killing of George Floyd. DHS created a task force to protect federal buildings and monuments, then deployed federal agents and officers in tactical gear to Portland, Oregon, where they clashed with demonstrators and arrested people using unmarked vehicles and without identifying themselves in ways that drew comparison to a secret police force.

The deployment of DHS personnel to Portland came despite the objections of state and local authorities, who said the federal agents had only inflamed the situation.

"The department's purpose, the reason we were created post-9/11, had everything to do with big picture terrorism, national threats," said Elizabeth Neumann, a former senior DHS official who left the agency in April. "We are always on call to provide support to our state and local partners. But the way our Constitution was written, and the framers intended, it's a state or locality's job to do policing and not the federal government."

Wolf dismissed the criticism in a speech this week, saying that those who "indiscriminately destroy businesses, and attack law enforcement officers" are a threat to the homeland.

Hours later, the Murphy complaint surfaced and gave critics more ammunition. It said Wolf and others sought to suppress information about Russian interference to avoid offending Trump and to downplay the threat of white supremacists and distort facts.

He said DHS officials also distorted statistics about the number of illegal immigrants with ties to terrorism to build support for the border wall but in a follow up on Thursday withdrew an earlier claim that Nielsen provided a false inflated statistic to Congress on the subject.

To the chair of the House Homeland Security Committee, Rep. Bennie Thompson, the whistleblower's complaint was another example of what he called "an apparent whole-of-government effort to help the president in his flailing reelection campaign."

The Mississippi Democrat called on both Wolf and Cuccinelli to resign. "Their toxic and unethical actions are wholly incompatible with the non-partisan mission of the Department of Homeland Security," he said.