Recall how Mr Obama won the presidency opposing gay marriage 回想一下，奥巴马是如何在反对同性结婚的情况下还赢得总统大选，

and Bill Clinton built a coalition in the centre-ground. 而比尔·克林顿又如何以中立立场建立起联合政府。

But rancorous political disputes—over guns, abortion and climate change— 但充满敌意的政治争端——控枪、堕胎、气候变化——

split so neatly along urban-rural lines that parties and voters increasingly sort themselves into urban-rural tribes. 却齐整地将城市和农村割裂开来，以至于越来越多的党派和选民自动将自己归于城市或农村阵营。

Gerrymandering and party primaries reward extremists, and ensure that, once elected, they seldom need fear for their jobs. “杰利蝾螈”（专为某方选举利益设计的选区划分方式）和党内初选都鼓励极端主义者，并且确保一旦当选，就很少需要为工作忧心。

The incentives to take extreme positions are very powerful. 采取极端立场的动机是非常强的。

Bitter partisanship, ineffective federal government and electoral bias poison politics and are hard to fix. 激烈的党派之争、低效的联邦政府和选举偏向性毒害了政治，而且很难修复。

Changing the constitution is hard—and rightly so. 修改宪法很困难——也理当如此。

Yet the voting system for Congress is easier to reform than most people realise, 然而，改革投票制度比大多数人想的要更容易，

because the constitution does not stipulate what it should be. Congress last voted to change the rules in 1967. 因为宪法没有规定投票制度应该是什么样的。国会上一次投票修改规则是在1967年。

The aim should be to give office-seekers a reason to build bridges with opponents rather than torch them. 这样做的目的应该是给参选者一个与反对者建立联系的理由，而不是全盘推翻。

If partisanship declined as a result, so would pressure on voters to stick to their tribe. 如果党派偏向因此而减少，那么选民各执一派站队的压力也同样会减少。

That could make both parties competitive in rural and urban areas again, helping to restore majority rule. 这样会让两方党派再次在农村和城市地区竞争，从而帮助恢复多数决定原则。

One option, adopted in Maine this year and already proposed in a bill in Congress for use nationwide, 缅因州今年采用的一种选择，已经在国会法案中提出以便在全国范围内采纳，

is "ranked-choice voting" (RCV), in which voters list candidates in order of preference. 这就是“排序复选制”（RCV），这个规则规定选民按照喜好列出候选人。

After a first count, the candidate with the least support is eliminated, 在第一轮计票后，获得支持最少的候选人遭到淘汰，

and his or her ballots are reallocated to those voters'second choice. 而其所获选票将重新分配给投票给他/她的选民的第二选择。

This continues until someone has a majority. 如此循环，直到一位候选人得到最多选票。

Candidates need second- and third-choice votes from their rivals'supporters, 候选人需从他们的竞争对手那里争取第二轮和第三轮的投票，

so they look for common ground with their opponents. 因此候选人会和竞争对手找共同点。

Another option is multi-member districts, which were once commonplace and still exist in the Senate. 另一个选择是复数选区制，这是曾一度流行、现仍存参议院的制度。

Because they aggregate groups of voters, they make gerrymandering ineffective. 因为选民人数众多，所以“杰利蝾螈”的策略失效。

Voting reform is not the whole answer to partisanship and built-in bias, but it would help. 改革投票制不会完全改变党派偏见与其内在偏向性，但会起到一定作用。

It is hard, but not outlandish. 尽管改革步履维艰，但并非天方夜谭。

To maintain the trust of all Americans, the world's oldest constitutional democracy needs to reform itself. 为保有所有美国人的信任，世界上最古老的宪政民主体制需自我革新。