By conventional standards, President Trump is not a very good politician. His legislative accomplishments as president have been meager and his international bargaining has been poor. But political scientists would acknowledge one area in which Trump has been adroit: He has colonized the Republican Party in every important way imaginable.

Outside of Sen. Mitt Romney (Utah), no GOP politician of national standing has consistently challenged the president. The few who rhetorically tangled with Trump in his first years in the White House — folks like Jeff Flake (Ariz.), Bob Corker (Tenn.) or Mark Sanford (S.C.) — are no longer in office. And the president is keenly aware of this fact:

Trump’s iron control over his party has enabled him to be a somewhat stronger president than devotees of Richard E. Neustadt would otherwise expect. Trump has been eager to expand executive branch powers and ignore Congress. He has declared dubious emergencies and run roughshod over laws such as the Administrative Procedure Act, counting on his appointed judges and Republican members of Congress to run interference for him. Sometimes this does not work; much of the time, however, it does.

The key is the GOP’s continuing fealty to Trump. But the poll numbers are the poll numbers, and they are bad for the 45th president. They show rising disapproval of the president, growing GOP dissatisfaction with the direction of the country and Trump falling further behind Joe Biden. It is therefore unsurprising that some cracks are forming in the edifice.

GOP strategists are grumbling to the Washington Examiner’s W. James Antle III about Trump’s repeated Twitter own-goals, for example. One GOP strategist told Antle, “[Trump’s] instincts and mistakes on Twitter have often brought him off message and made him often look unfocused and small, like a very average politician on Twitter instead of the president of the United States.”

But that is small potatoes compared with some other areas where senior members of the GOP are starting to push back on president Trump. There is the wearing of masks, for example. In a Wall Street Journal interview earlier in June, Trump suggested that some Americans were wearing masks not for any health reason but rather to register disapproval of him.

If that is true, then an awful lot of Republicans disapprove of Trump. According to the Wall Street Journal’s Catherine Lucey, “A growing chorus of Republican officeholders and conservative media figures are calling for people to wear masks to prevent the spread of coronavirus ... with some urging President Trump to publicly wear one as cases soar around the country.”

This includes Fox News hosts such as Sean Hannity and Steve Doocy, Senate Majority Leader Mitch McConnell (R-Ky.), the U.S. surgeon general and conservative stalwarts like the Cheneys. The most prominent shift comes from Vice President Pence, however. According to Politico, Pence over the weekend shifted his emphasis from reopening the country to wearing masks. This part is particularly interesting: “Pence’s pro-mask endorsement drew praise from corners of the administration on Monday. One senior administration official said it was ‘a step in the right direction that President Trump should also take.’ ” It jibes with what my Post colleagues Philip Rucker and Seung Min Kim report: “The recent shift on the political right has left Trump isolated, with the president and his White House staff openly resisting the calls for mask-wearing.”

Meanwhile, senior GOP members of Congress are also prodding the White House for more information about intelligence that Russia offered the Taliban bounties to kill U.S. soldiers in Afghanistan. Since the New York Times broke this story last week, the Trump administration has been playing a losing game of “not it.” First they denied that the intelligence was very good, which led to multiple confirmations of various aspects of the story. Then they denied that the president had been briefed, which led to reporting that the information was put in the President’s Daily Brief this past February and that he had been briefed on this as early as 2019.

As the Trump White House loses the information war, Republican members of Congress are starting to say stuff. According to Politico’s Andrew Desiderio and Marianne Levine:

Key committee chairs made clear on Monday that they will press the White House for answers about the intelligence assessments, and GOP senators pushed President Donald Trump to exact severe punishments on the Kremlin if the claims are true — even as the president asserts that he was never briefed on the matter …
The Senate GOP’s pressure on the White House could reopen a rift between Trump and Republicans when it comes to the U.S. relationship with Moscow. Congressional Republicans, including Rubio and other GOP leaders, have typically shown more antipathy and distrust toward Russia than the president....
Moreover, many Republicans do not appear to be taking the White House’s pushback at face value, with some arguing that the president should have been briefed on an issue as serious as this one.

Let’s be clear: The Republicans have not completely turned on Trump and in many ways are aiding and abetting his derelict behavior. Still, fissures are fissures, and they are even spreading to the executive branch.

There is a snowball effect to some of this. The more that Republicans dissent from Trump, the weaker he looks politically. The weaker he looks politically, the more Republicans might dissent from him to get ahead of bad news.

Just imagine how this dynamic plays out if Trump’s approval rating sinks even further.