The charges filed against three Trump campaign officials this week have widened the partisan divide over congressional investigations into Russia's election meddling, as Democrats charge Republicans are trying to wrap up the probes before lawmakers know the full extent of special counsel Robert S. Mueller III's investigation.

Republicans insisted this week that Mueller's work will not dictate the timeline of the inquiries being run by three separate congressional committees, arguing the investigations should proceed independently.

"They're really apples and oranges," said Sen. John Cornyn (R-Tex.), the Senate's second-highest-ranking Republican and a member of both the Intelligence and Judiciary committees. "Once we feel like we've exhausted all of our leads and figure out what Russia is up to and who is involved — when we complete our task, I wouldn't tie it to Mueller's investigation."

GOP leaders are looking to complete the investigations in the next few months in hopes of putting the issue to rest far ahead of the 2018 midterm elections, but Democrats are seizing on this week's charges as evidence that Mueller knows more about potential ties between the Trump campaign and Moscow than Congress — a reason the inquiries should be kept alive.

"We'd be foolish to stop," said Sen. Richard J. Durbin (D-Ill.), the Senate's second-highest-ranking Democrat and a senior member of the Senate Judiciary Committee, one of three congressional panels looking into Russian meddling. "We're going to learn with the indictments, things we don't know. There's a limit to what these investigative committees can subpoena and do. . . . [Mueller's] going to have a lot more access to information than any congressional committee."

While Republicans see an advantage to completing the congressional work soon, in doing so they also run the political risk of being embarrassed if Mueller later unearths critical information about Russia's role in the election that was not included in the final reports from the committees.

For now, key GOP senators said that is of little worry to them.

"I think we're still ahead in many ways of where [Mueller's] investigation is," said Senate Intelligence Committee Chairman Richard Burr (R-N.C.). He stressed that "the committee has always had the task of investigating thoroughly enough that we didn't think anything else would be found that we hadn't found."

Burr said his panel tried to interview people it assumed might be targets of Mueller's criminal inquiry early on — it becomes difficult for congressional panels to secure interviews with potential witnesses once they have been charged.

Several Republicans are also questioning whether it is worth waiting for Mueller's next revelation, pointing out that the charges filed this week against former Trump campaign chairman Paul Manafort and his business partner, Rick Gates, are for crimes allegedly committed before the campaign began.

Democrats dismissed this argument, noting that court papers filed this week along with a plea agreement for former Trump campaign adviser George Papadopoulos show Mueller is homing in on evidence that the campaign worked with Russians to influence the election.

In the court filing, Papadopoulos admitted he lied to FBI agents about his contacts with Russians, through whom he proposed brokering a meeting between Trump and Russian President Vladi­mir Putin. Democrats have already criticized Attorney General Jeff Sessions for not disclosing he took part in the meeting in which Papadopoulos raised the possibility of a Trump-Putin get-together. They said Mueller may have much more on the topic that he has not publicly disclosed.

"It would be incredibly embarrassing to close out the congressional investigation without knowledge of Papadopoulos — you know this is, along with the Don Jr. meeting, the clearest evidence leaning toward cooperation," said Rep. Jim Himes (D-Conn.), a member of the House Intelligence Committee. He referred to a June 2016 Trump Tower meeting attended by a Russian lawyer, Donald Trump Jr., Jared Kushner and Manafort.

Himes also questioned "whether it's a coincidence that just as the Republican majority begins the drumbeat of 'we gotta wrap this up,' you've got a truly dramatic development that is squarely within the strike zone of our investigation."

The Papadopoulos charges were not a surprise to every investigating panel: The Senate Intelligence Committee tried, and failed, to schedule an interview with him, according to a person familiar with the inquiry. The committee is aiming to wrap up its investigation by mid-February, according to Burr, unless new witnesses come to light.

For now, the only new witnesses Republicans across the three panels are focusing on are people they believe can shed light on payments the Democratic National Committee and Hillary Clinton campaign made to support the production of a dossier that details alleged ties between Trump and Russian interests.

"We're moving forward as quickly as we can. What does affect us is the disclosure by The Washington Post that Democrats may have been paying for the dossier," said K. Michael Conaway (R-Tex.), who is running the House Intelligence Committee's Russia probe.

As for Mueller's investigation, Conaway added that "he's going to be doing that typically for a long time; I want to get our stuff quicker than that."

The House Intelligence Committee and the Senate Judiciary Committee have already partially turned their attention elsewhere, announcing new investigations last month into the Obama administration's approval of a 2010 deal allowing a Russian company to purchase a Canada-based mining group with uranium operations in the United States.

Democrats on those panels have objected and threatened to press forward with the Russia investigations alone, despite having no independent power to subpoena testimony or documents.

Republicans said that even in the event Mueller uncovers new information months from now after congressional investigations have been concluded, it's preferable to reopen an inquiry than let current ones linger indefinitely.

If "we issue a report, and, you know, a year later or whatever, Mueller comes through with something that's 180 degrees the other way or different, and we have to say, okay, he came by that information later?" Conaway said. "It's an open question . . . a question we're going to have to come to grips with."