When the Founders wrote the Constitution, travel was hella hard in the US. It could take a long time. Thomas Jefferson lived only 116 miles from The White House, but each round trip took him 8 days and 6 nights in travel. Once elected to federal office, Americans had to put their affairs in order and make a really long trip if from the more outlying states, from where reaching the capital could take weeks.
The Constitution also required Congress to convene only once a year, in December. That meant after elections, the outgoing session met in December, but newly-elected members might not actually start work until December a year later. And in presidential election years, the office of the chief magistrate hung in limbo from November to March. How bad this could be was illustrated twice: in 1860-61, when President Buchanan, leaving office, could take no action to stem the secession of southern states; and in 1932, when President Hoover, defeated by Franklin Roosevelt, spent the interregnum trying to pin Roosevelt down to a deal to continue the Republican policies that had so manifestly failed.
The latter crisis proved decisive, and the beginning of congressional sessions and the inauguration of presidents was moved to January by the 20th Amendment.
Another feature of long congressional recesses is the Recess Appointments Clause. In the age of sudden death, federal jobs needed to be filled. So the Constitution allowed the President to make appointments to serve until the end of the congressional session then meeting if the Senate was away.
Since 2007, the Democrats and Republicans alike have used the device of pro forma Senate sessions, in which one senator gavels the body into session each day during vacations. This expedient worked well in an increasingly take-no-prisoners approach to frustrating presidents of the other party.
Now, of course, we have Congress and the Presidency in the hands of the same party.
It is, therefore, no surprise that the President's advisors are talking of forcing out Attorney General Sessions once the Senate leaves- shortly, one assumes- for its delayed August recess, and during that recess (left happily un-pro-forma'd by Senator McConnell) the President can circumvent a very untidy confirmation process for a successor.
A successor, who, among other things, would 1/ serve without confirmation until January 2019, and 2/ could fire the Special Counsel, Robert Mueller, and shut down the Russian investigation.
His supine congressional party- who use him, and let themselves be used- to enact decades of old score-settling laws against the poor and minorities, as well as more modern fantasies Paul Ryan got off to while reading Ayn Rand as a teen, will then say,"Nothing to see here," and pack their tents to work on stuff like more tax cuts and the Jesus Discriminates Religious Freedom Law.