In the Gilbert and Sullivan operetta HMS Pinafore, Sir Joseph, a former member of the British Parliament who has been appointed lord admiral of the queen's navy, recalls how he achieved such great success: "I always voted at my party's call," he sings, "and I never thought of thinking for myself at all."

Sir Joseph would fit in well in the United States' party-driven political system, in which loyalty to one's political club often seems to trump objective decision-making.

When a Senate committee voted in favor of Sonia Sotomayor's confirmation for a seat on the Supreme Court, every Republican but one voted no, even though she was obviously qualified and even her most insistent critics could find few decisions to quarrel with over a long career. And not one Democrat voted no, even though Sotomayor had repeatedly indicated in speeches that a judge's background matters more than strict adherence to the law. There were party lines to be followed, and the senators followed them.

Last month, when another Senate committee became the first to pass a health-care reform bill, not a single Democrat thought questions about the proposal, which included a government-run plan, were sufficient to raise doubts. Not one Republican thought the current state of American health care justifies the legislation.

If legislators decided how to vote by weighing the concerns of constituents, their own philosophies, and a proposal's merits, one might assume that at least one or two Democrats would have balked, and a Republican or two would have voted to go forward. But we don't live in that kind of political world.

The Washington Post reviewed Senate voting records during the last Congress, which included important votes on wars in Iraq and Afghanistan, billions of dollars in spending, and many other difficult issues. On average, Democrats voted with their party 87.5 percent of the time, and Republicans 80.7 percent of the time; 44 senators voted with their party more than 90 percent of the time, and 24 more than 95 percent of the time. So-called maverick John McCain voted with Republicans more than 88 percent of the time.

Granted, there are distinctions in political philosophy that draw people to one party or the other, but it is nonetheless clear that there is far less independent thinking going on than good governance would demand.

When I testified before the House Judiciary Committee against President George W. Bush's unconstitutional use of "signing statements" suggesting he might not be bound by the laws being enacted, not a single Republican on the committee saw anything wrong with what the president had done. They later found the same practice unlawful when a Democratic president did it. When the House voted to hold White House staffers in contempt for defying a congressional subpoena, Republicans stomped out in protest.

At the time, I saw those incidents as signs that my fellow conservatives had abandoned their principles. But it was more than that: It was one more example of members of Congress voting as a team. Surely, when Bush's assistants defied congressional subpoenas, at least a few Democrats might have thought a president's claims of executive privilege had some merit, and a few Republicans might have been appalled at a chief executive thumbing his nose at the lawmaking branch. But, again, that's not the world we live in.

James Madison and George Washington feared the advance of political parties. Of course factions would be formed, they thought; people of like interests would band together. But the coalitions would shift as issues shifted. In a system designed to leave the people in charge, their representatives would assess issues and vote according to their best judgment.

Loyalty to party undermines the very essence of representative government, which depends on entrusting members of one's community to act in one's stead. What author Peter Shane labeled Madison's Nightmare has come true: We live in a world of constant partisan warfare, a never-ending battle between clubs, undermining the belief that a citizen's vote truly counts for something.

Political theorist Bernard Crick wrote that "politics is how a free people govern themselves." Strong political parties, on the other hand, are how a free people lose that ability. Parties choose which candidates can be on the November ballot, and do so in primaries and conventions that cater to the extremes. Parties reward fealty and discourage independence.

In an earlier time, when it was hard to get information about candidates and they had to depend on party funding and volunteers, political parties made sense; today, they are remnants of a time that has passed.