The script has become familiar by now. A new controversy, usually involving Russia, stirs within the White House, consumes a news cycle and spills out onto the feet of congressional Republicans, leading to the question: When will lawmakers break from Donald Trump?

While Republican members of Congress may squirm or wring their hands at the latest news and take to Twitter to air their grievances about the president, there is not yet a political incentive to file for separation in this marriage—even if it is an arranged one.

Over the course of a chaotic six months of this presidency, Trump's approval rating among Republicans has remained consistently strong at around 85 to 90 percent. While his support nationally hovers around 40 percent and some polls show him losing ground among independents, Republicans across the country still back him and, therefore, their representatives in Congress continue to do so as well. Severing themselves from Trump would be to alienate his supporters who significantly overlap with the Republican Party base.

And as GOP lawmakers gripe about a stalled or distracted agenda, there is still a Republican behind the Resolute Desk, ready to enact (most) of the legislation they send to him. "I am sitting in the Oval Office with a pen in hand, waiting for our senators to give it to me," Trump said of the health care bill in an interview with the Christian Broadcasting Network on Wednesday, warning the Senate majority leader: "Mitch has to pull it off."

So long as Trump's agenda doesn't diverge from that of Republicans, members of Congress are inclined to see the relationship through.

"The relationship has always been largely transactional," said GOP strategist Alex Conant. "Republicans in Congress can pass laws and Trump can sign them. Therefore it’s mutually beneficial."

Further, there is a sentiment among the party base that the president is a sympathetic character.

"Republicans see him as victimized to a degree and want him to succeed," said Oklahoma Rep. Tom Cole, a House leadership ally, even as he acknowledged "there’s so much other news coming out of the White House, it does take the focus off [agenda items], and that hurts."

"This has taken so many twists and turns, but whatever it is, we haven’t reached it yet," Cole said when asked whether there would be a breaking point for congressional Republicans.

Scott Jennings, a Kentucky-based Republican strategist and veteran of the Bush administration, said there is a "tribalism of trust" in politics, particularly among supporters of the president.

"The Russia story is largely playing out as a result of the investigatory work of a few media outlets that Republicans just don’t trust," Jennings said. "The vast majority of Republicans at best view that with a skeptical eye."

These various dynamics help explain why most Republican lawmakers ducked reporters or shrugged when faced with news this week that the president's older son, Donald Trump Jr., met with a Russian attorney he hoped would provide incriminating information about Hillary Clinton during the campaign—a development that not only fueled allegations of collusion but also flew in the face of statements by the president and White House officials denying any such meetings.

Republican leaders and members of the rank and file on Capitol Hill this week have invariably argued that however concerning this new development, they would reserve judgment until Russian investigations by congressional committees and a special counsel are complete.

The president's son has also become a fan favorite among the base of Trump supporters, having carved out a role as an attack dog against the media. Various figures in Trump's orbit, including media personalities, have risen to Donald Jr.'s defense.

"We have three investigative bodies looking into all of this, and if they think it’s important, they will bring him in," said Georgia Sen. David Perdue. "Mike Huckabee made a great point this morning when he said to compare this to Hillary’s thousands of pages of emails we didn’t get access to, and here’s a kid that is voluntarily putting it out there."

"We’re not distracted by it," Perdue said when asked whether the controversy interrupted the GOP agenda.

Ted Cruz, who once called Trump a "sniveling coward" during the GOP presidential primary, deflected questions about the Russia controversy involving the Trumps.

"It's just worth keeping in mind the absolute disconnect between the obsession of the Washington media and where the American people are," he told reporters. "We have had eight years of Barack Obama showing nothing but an appeasement of Russia."

Alabama Rep. Mo Brooks said it is "the intent of the news media and the Democrats to make it a distraction, instead of focusing on issues of substance like deficit and debt and the debt ceiling, infrastructure, tax reform, border security."

"My state overwhelmingly supports Donald Trump," he said. "There are thousands upon thousands of issues, so [the Russia probe] falls in the category of thousands upon thousands of issues."

Brooks is running in a Republican primary for a Senate seat occupied by Luther Strange, who filled a vacancy created by Jeff Sessions' appointment as attorney general. The primary has become a contest to determine who can better tie himself to Trump. On Wednesday, for example, the Senate Leadership Fund, a super PAC affiliated with Senate Majority Leader Mitch McConnell, hit Brooks for not endorsing Trump and for not previously supporting his call for a border wall with Mexico.

Brooks said he would support a sanctions bill against Russia, but in response to Putin's aggression in Ukraine, not necessarily because of election meddling.

The Russian sanctions bill, which passed with 98 votes in the Senate and awaits approval in the House, represents one of the few instances in which GOP congressional interests collide with Trump's.

And on health care, Senate Republicans are more concerned about the substance of the policy than the president, who is eager to claim a legislative victory and has done little to sell the merits of the bill.

But differences between Trump and his Republicans in Congress aren't yet irreconcilable enough to warrant a divorce.

"The moment that Trump’s agenda stalls out, and it becomes clear supporting him will no longer lead to great conservative legislative victories, the relationship will change for the worse," said Conant. "I don’t think Trump’s agenda is dead by any means."

That doesn't mean the relationship is a pleasant one, Conant said. Indeed, it is complicated. Republicans fought Trump's eventual nomination, and he ran against the party in many ways. Unlike President Obama's relationship with Democrats or George W. Bush's relationship with Republicans, there isn't much built-up goodwill or ideological alignment between this president and lawmakers from his party.

But Republicans have done little, except rhetorically, to truly defy the president. Most senators have voted with the president at least 90 percent of the time, according to analysis of voting records by the site FiveThirtyEight.com. Only Sens. Rand Paul and Susan Collins haven't matched that number, but still register around 86 percent. Senators including Lindsey Graham and Ben Sasse have become top critics of the president and administration, but have voted in support of him 94 to 96 percent of the time.

Granted, there is not an abundance of legislation to vote on, and many of these votes were for Cabinet or executive positions, but they reflect a general pattern of supporting a president from the same party.

"It’s a rare moment in American politics for people in a political party to fully abandon their leadership. The president, no matter who it is, is the titular head of his party," said Jennings.

And as head of the party, strategists say, Trump can be a powerful force for the GOP. In assessing lessons learned from this year's special elections, Mike Shield, a former chief of staff to the Republican National Committee, and Rob Simms, the former executive director of the National Republican Congressional Committee, argue Republicans would be unwise to cut ties with the president.

"Republicans need every part of the Republican coalition to win elections—including, and sometimes especially, those voters who supported President Trump in 2016," they wrote. "Don't play a game of trying to distance yourself from the President. Regardless of what commentators say on TV, this is not a winning strategy. You do not gain any new votes, and you alienate yourself from voters who are inclined to vote for you."

GOP lawmakers are aware of the political perils of returning to constituents empty handed after gaining control of both Congress and the White House, and acknowledge that the controversies hovering at the other end of Pennsylvania Avenue aren't all that helpful.

"I don’t think they’re happy with the pace of things. I’m not happy with the pace of things," said Louisiana Sen. John Kennedy. "We just haven’t made enough progress."

Kennedy said the Russia investigations are important and warrant attention, even if they overshadow other happenings on the Hill.

"Having said that, when moms and dads lie down at night in Louisiana and can’t sleep because they’re worried, they’re not worried about the Russia investigation," he said. "They figure the FBI is going to take care of that. They are worried about their health care and their job and how they’re going to afford their kids' education and how they’re going to live after they retire."