Among some there is the belief that to be effective, a lawyer has to be connected. I.e.: he/she needs to have positive, productive relationships with the local PTB.
The simple truth is that in DC it is far easier to be connected as a Democrat than as a Republican. DC is a liberal Democrat town. It’s that way when the Democrats are in charge, and it’s that way when the Uniparty is ostensibly in charge. It shouldn’t be this way, but it is. Facts are facts.
Most top Republican lawyers have no interest in working in that hive of scum and villainy. You’re more likely to find them in the general counsel roles of major U.S. corporations than dealing with scumbags in Washington D.C.