Does the franking privilege allowing Congress members to mail items for free help prevent proportional representation in the U.S.

Non-sequitur. It is an advantage to incumbents, but that does not “prevent proportional representation”, nor does it directly bar independents.

Besides, with the level of hyper-scrutiny these days, people actually abusing it could suffer an opinion disadvantage that could out-weigh the effect of free junk mail postage.

Technically, the franking privilege is not extended to “campaign” materials, but… it’s no coincidence that I get more “news from Congress” in the Fall than I do at any other time of every year. They may be idiots in Congress, but they’re not fools. Or maybe I misworded that… vice versa and all.

A bigger issue to me would be how parties in power (most recently the Republicans over the last 10 years) zone the districts to favor their party.

For example you’ve got a big city like Columbus (my city). Its surrounded by large rural areas for quite a ways in every direction. Not surprisingly the city is largely liberal/democratic/left and the rural areas are largely conservative/republican/right. Combined the areas have enough population for two zones and hence two seats in congress. Now rather than split this into the city and the rural areas, essentially guaranteeing each party one seat and guaranteeing that the majority of people in those respective areas have their choice for candidate in office…. The Republicans some years ago zoned it so that Columbus is sliced right down the middle, and each half is combined with half of the rural area… plus just a bit more rural area.

The result is 2 seats that are almost always Republican, even though the vast majority (70+%) of the cities voters, whom would themselves have enough populace for one congressional house seat, have no voice in congress.

The party in power does everything it can to remain the party in power. This was a particularly bad time to lose to Republicans, since the Republicans will now get to Gerrymander all the districts so as to be an advantage to their side.

Franking is just one more advantage that incumbents have. Yes it allows them to communicate with voters at election time and to crow about all their accomplishments. It may be an unfair thing, but is it a bad thing? Is it bad to have the best Congress critter money can buy? I can’t say for sure.

As @wundayatta and @tedd point out, holding state governorships and a majority in state legislatures is the tool of choice to help keep your party in power. They get to redraw congressional districts in absurd shapes designed to lump just the right mix of voters together so they will always win the majority of seats in the upcoming election. It’s supposed to be illegal, but courts ignore it with a win and a nod. Some districts are only half a street wide for miles on end and courst still hold that no Gerrymandering is going on.

I doubt that the franking privilege does much for representation. What is really harmful is the way that districts are redrawn. Some states regulate this to insure that the districts are logical and contiguous. Others allow free range gerrymandering with districts drawn to insure the continued success of the incumbent or the advantage of the majority party. It is just another way to whittle away at our freedom.