While the State Department plays a key role in the immigration process (both because of visa screening overseas and its role with refugees), the secretary spends only a tiny fraction of his or her time dealing with migration issues.
Nevertheless, the background and the policy attitudes of that official can play a major role in setting the atmosphere in which junior diplomats make individual visa decisions.
Newly designated Secretary of State, former Rep. Mike Pompeo (R-Kan.), — currently the CIA director — comes to the office with a far-different background than many of his predecessors. Unlike Henry Kissinger (R) and Madeline Albright (D), who were born within a couple of hundred miles of each other in Bavaria and the Czech Republic, respectively, Pompeo is native-born (from conservative Orange County, Calif.) Unlike John Kerry (D), who is fluent in French, Pompeo has no known language skills. Unlike former Secretaries Condoleezza Rice and Colin Powell, he is not a member of a minority.
Wikipedia reports that one of his grandparents, his paternal grandmother, was born in Italy, suggesting that the other three, as well as both of his parents, were born in this country.
He is a former Kansas businessman who served three terms in the House, representing, among others, his state's wheat farmers. He went to West Point and served in the Army. He took over at the CIA in January of last year, shortly after President Trump's inauguration. Blurring this picture a bit, he (like Barack Obama) has a degree from Harvard Law School.
It is from this background that his immigration policy views have emerged. According to NumbersUSA's always useful Immigration-Reduction Report Card, he has a solid A career rating for his six years in the House of Representatives. His score of 91 percent puts him in fifth place among his 14 colleagues as former members of the Kansas delegation.
While routinely in favor of stricter immigration law enforcement, he also voted for the Trade Promotion Authority bill, HR 2146 in 2015. That legislation, like some other trade bills, gave the president authority to expand immigration levels without consulting Congress.
In the late summer of 2016, when the surge of refugees into Europe from the Middle East was at its height, Pompeo and Sen. Tom Cotton (R-Ark.) paid an immigration policy visit to Norway and Sweden, two adjacent and similar nations (once a single entity), to examine those nations' quite different refugee policies.
They concluded, in an op-ed written for the Wall Street Journal, that Norway's more cautious approach compared to Sweden's open-door policy had benefited the former nation, and reflected a more open political system, in which restrictionist parties worked closely with other political forces, as opposed to their being shunned, as they are in Sweden.
Interesting field work for a potential Secretary of State.