WASHINGTON — Republican congressional aides have set their iPhones to flutter every time President Trump hurls a thunderbolt on Twitter. Senators nod politely at his false claims of mass voter fraud during private White House meetings. The congressional morning briefing literature now includes a rundown of overnight and early-morning social media missives from the commander in chief.

“It doesn’t take that long to read ’em,” said Senator Bob Corker, Republican of Tennessee.

After three weeks in the White House, Mr. Trump has made clear that he is going to continue promulgating conspiracy theories, flinging personal insults and saying things that are plainly untrue. And the Republican-controlled House and Senate seem to have made a collective decision: They will accommodate — not confront — his conduct as long as he signs their long-stalled conservative proposals on taxes, regulations and health care into law.

“There’s a widely held view among our members that, yes, he’s going to say things on a daily basis that we’re not going to like,” said Senator John Thune of South Dakota, the third-ranking Senate Republican, “but that the broad legislative agenda and goals that we have — if we can stay focused on those and try and get that stuff enacted — those would be big wins.”

Such accommodation is coming at a price, attracting incredulous or angry constituents to town hall meetings, leaving members flat-footed when presented with the latest presidential provocation and testing the capacity of now perpetually clogged phone lines on Capitol Hill.