WASHINGTON — Hours before President Donald Trump announced him as the pick to be the new director of national intelligence, Rep. John Ratcliffe was on Fox News saying the Russia investigation may have been tainted by a criminal conspiracy.

"What I do know as a former federal prosecutor is that it does appear that there were crimes committed during the Obama administration," the Texas Republican said Sunday, speaking about the origins of the FBI's investigation into Trump campaign contacts with the Russians.

Ratcliffe didn't specify which crimes, and he didn't offer any evidence. None have surfaced on the public record.

But statements like that from Ratcliffe, rated one of the most conservative Republicans in Congress, are causing disquiet among current and former intelligence officials, who worry that as the nation's top spy Ratcliffe will politicize what is supposed to be one of the most nonpartisan jobs in Washington.

"Mr. Ratcliffe appears to be somebody who is more interested in pleasing Donald Trump," President Barack Obama's CIA director John Brennan, an NBC News analyst, said on MSNBC.

The intelligence community will fight hard against a threat to its culture of avoiding open partisanship, former senior CIA operations officer John Sipher told NBC News. "It's all about professionalism and taking the world as it is. There is no such thing as Democratic or Republican intelligence. It is what it is, no matter how inconvenient."

Dan Coats, the former Indiana senator whose departure as DNI paved the way for Trump to pick Ratcliffe, appeared to live by that code. He discussed intelligence assessments in public that were at odds with Trump's worldview, and he focused on the issue of Russian election interference, an issue Trump appears to view as a threat to his legitimacy. As NBC News has previously reported, that candor contributed to a strain between Coats and Trump that led to the former's departure.

Ratcliffe, by contrast, has focused on what he believes was misconduct at the heart of the Russia investigation and has spent little time talking about Russia's interference in the American political system.

In last week's hearing with former special counsel Robert Mueller, Ratcliffe attacked the premise of Mueller's report and accused Mueller of violating special counsel rules. He also questioned whether Russia provided false information to a former British intelligence officer who wrote an infamous dossier, which Republicans have sought to portray as a key aspect of the Mueller probe, but which FBI officials say played a minor role.

"I very much agree with your determination that Russia's efforts were sweeping and systematic," Ratcliffe told Mueller. "I think it should concern every American. That's why I want to know just how sweeping and systematic those efforts were. I want to find out if Russia interfered with our election by providing false information through sources to Christopher Steele about a Trump conspiracy that you determined didn't exist."

Ratcliffe, 53, has little experience in national security or intelligence. He was elected in 2014 with the support of the Tea Party, ousting 91-year-old incumbent Republican Ralph Hall. Ratcliffe had been the mayor of Heath, Texas — population 7,000 — from 2004 to 2012.

During that time, Ratcliffe became a federal prosecutor, named chief of anti-terrorism and national security for the Eastern District of Texas. In 2007, Ratcliffe was named the district's acting U.S. attorney by President George W. Bush.

Although Ratcliffe's website says he "put terrorists in prison," there is no evidence he ever prosecuted a terrorism case.

While he was U.S. attorney in East Texas, Ratcliffe was appointed as a special prosecutor in a terrorism funding case in Dallas, U.S. v. Holy Land Foundation, in which a Muslim charity was found guilty of funneling money to the Palestinian terror group.

A 2015 news release said, "He convicted individuals who were funneling money to Hamas behind the front of a charitable organization."

But Ratcliffe's name does not appear in the Holy Land trial record. Asked about that, his spokesman said Ratcliffe was appointed by the attorney general to investigate what went wrong in the first of two trials in the case, which ended in a mistrial.

A former Justice Department official said Ratcliffe was appointed by Attorney General Michael Mukasey as a special prosecutor to look into allegations, involving a juror and one of the defendants, that surfaced after the first prosecution of the Holy Land Foundation ended in a mistrial.

“Nothing came of it,” the former official said. He said Ratcliffe made no recommendations and was not involved in the retrial that resulted in convictions.

When Obama took office, Ratcliffe went into private practice, forming the firm Ashcroft, Sutton, Ratcliffe — a Texas outpost of the Washington, D.C., law firm founded by former Attorney General John Ashcroft.

He served briefly on Mitt Romney's presidential campaign in 2012.

Ratcliffe's once completely rural district is now partly a distant suburb of Dallas. Trump won 75 percent of the vote there in 2016. The population is 73 percent white, according to the Almanac of American Politics.

Reactions from Republicans to Trump's selection of Ratcliffe were tepid. Sen. Richard Burr, R-N.C., the chairman of the Intelligence Committee, which will hold Ratcliffe's confirmation hearing, waited a day before congratulating Ratcliffe in a statement that did not quite endorse him.

Burr made a point of praising the deputy director of national intelligence, Sue Gordon, a former CIA official who is widely respected throughout the government. It's not clear that Ratcliffe will keep her in place, and Trump did not say whether he would name her as the acting director before Ratcliffe is confirmed.

"I can tell you this — if he appoints anyone other than Sue Gordon as acting DNI, the Senate will raise holy hell," a Democratic congressional official said.

Former federal prosecutor Chuck Rosenberg interacted with Ratcliffe when Ratcliffe was a U.S. attorney and Rosenberg was at the Justice Department.

"Prior to the Mueller hearing, if somebody had asked me about John, I would have said he was an honorable and decent guy," Rosenberg, now an NBC News analyst, said. "I thought his treatment of Mueller was unfair, disingenuous and wrong, and it gives me pause."