Indeed, Ms. Kagan gave as good as she got. Later in her presentation, Justice Scalia again interrupted, to remind her that there are reasons to be suspicious of Congressional regulation of campaigns: 'I doubt that one can expect a body of incumbents to draw election restrictions that do not favor incumbents,' Justice Scalia said. He then asked, rhetorically: 'Now is that excessively cynical of me? I don’t think so.' Ms. Kagan, without missing a beat, shot back, 'I think, Justice Scalia, it’s wrong.'
Kagan's argument is not a point of view with any basis in fact. There are a plethora of ways to show that incumbents favor themselves over potential opponents, but the point is made best graphically below, with a depiction of Pennsylvania Congressional District 12 (click to enlarge), surrounded by rival party districts:
Or North Carolina's Congressional District 12 (click to enlarge):
Or Illinois's Congressional District 4 (click to enlarge):
These are samples of districts that have been deliberately drawn to give one party an electoral advantage--the first for John Murtha, the second a district that had been repeatedly struck down as racially gerrymandered throughout the 90's until it was decided that racially-focused partisan gerrymandering was constitutional. The third is another racially-focused partisan gerrymandered district. No thinking, ingenuous individual could think that politicians do not favor themselves.