Republican strategists told the Washington Examiner on Tuesday that reports that President Trump inappropriately shared classified intelligence with Russian officials in an Oval Office meeting undermines his standing with Republicans and independents ahead of the 2018 midterm elections.

Republican insiders have become accustomed to Trump controversies, and usually downplay them because the president has weathered so many. But this issue, especially on the heels of Trump's firing of FBI Director James Comey, could sting if the president doesn't dramatically change course.

"This one has the potential to be different," said a Republican operative who advises GOP campaigns. "Every other time we've experienced nothing but turbulence, which is a recurring problem in air travel and poses no danger. This one feels like it might be a red light on the dashboard."

This Republican and others would only speak on condition of anonymity because they did not want to publicly criticize Trump.

The White House was reeling from a Washington Post report that Trump shared classified intelligence with the Russian foreign minister and ambassador to the U.S. The intelligence Trump discussed was provided by a foreign partner, which had not given permission for the information to be relayed, a major break with protocol.

The episode could damage Washington's relationship with this and other foreign partners and put sources and methods of intelligence gathering at risk of discovery. The news was revealed in the midst of continuing fallout from Comey's dismissal, coming as it did in the middle of an FBI probe of Russian meddling in the 2016 elections.

Trump's political standing has taken a hit, and voters haven't even had an opportunity to assess and digest this new crisis.

"The last couple weeks have left a mark," a GOP consultant said. "The risks of going down the present path include diminished enthusiasm in the base, low fundraising and candidate recruitment problems in down ballot races."

Trump's job approval in the RealClearPolitics average stood at 40.7 percent, dangerous territory for House and Senate Republicans in the midterm if the president can't right his ship in the intervening period.

The Democratic firm Public Policy Polling released a new survey showing Democrats with a 49 percent to 38 percent lead on the generic ballot. Republicans may quibble with PPP's liberal affiliation, but numbers like these will encourage Democratic fundraising and candidate recruiting, and could leave Republicans dispirited.

Republicans fear these new controversies will diminish Trump's support among traditional GOP voters who disagree with him on foreign policy as well as Republican leaners who are unsure of his fitness for the presidency.

These voters, combined with Trump's base, form the backbone of his coalition and that of his party in Congress. Republican strategists believe they have resigned themselves to the constant tweeting and other uncomfortable aspects of the president's personal style, but worry perceptions of foreign policy incompetence could cost them much needed support.

If Republicans in Congress begin to fear that that's what's happening, they'll abandon Trump on Capitol Hill, GOP sources say. This will deprive him of the legislative wins he needs to maintain his strength with soft Republicans and independents.

"I think we could do with a little less drama from the White House on a lot of things, so that we can focus on agenda, which is deregulations, tax reform, repealing and replacing Obamacare," Senate Majority Leader Mitch McConnell, R-Ky., said in an interview with Bloomberg.

Al Weaver contributed to this report.