It gets boring constantly beating on the Republican Party for their racism and general intolerance, but it’s an important feature of our national political landscape. The occasion of Sen. Edward Kennedy’s death is an appropriate time to do retrospective pieces on the myriad ways that the upper chamber has changed in the last half-century, but such analysis should mention how the two major parties have changed during that time.

Take a look at the elected officials in the GOP. There are no black Republican members of Congress. With the retirement of Sen. Mel Martinez of Florida, there are no Latino Republicans in the Senate. The only Latino Republicans in Congress are the three Cuban-American representatives from the Miami area. There are no Mexican Republicans or Puerto Rican Republicans. Now that Arlen Specter has switched parties, the only Jewish Republican in Congress is Rep. Eric Cantor of Virginia. I can’t think of any Republicans of East Asian ancestry other than freshman Rep. Joseph Cao of New Orleans. There are no openly gay Republicans in Congress. And consider this:

In the House there are 75 female Representatives. The Senate has 17 females. These are the highest numbers of women Members in the history of the Congress. Of the 17 female Senators, 13 are Democrats and 4 are Republicans. Of the 75 female Representatives, 58 are Democrats and 17 are Republicans.

The demographics of the country and the degree of female participation in politics have changed dramatically since 1962 when Ted Kennedy was first elected to the Senate. So, too, has that tolerance for gays and the rights of racial and religious minorities. But it seems like the Democratic Party has absorbed all of that change, while the Republican Party has been trapped in amber. The two Muslims in Congress are Democrats. The two Buddhists in Congress are Democrats. The three Unitarians in Congress are Democrats. The only averred atheist in Congress is a Democrat.

The Republican Party is hostile to non-white immigration. It considers religious tolerance to be an infringement on the free exercise of Christianity. It opposes gay rights and hate crimes legislation. And it holds anachronistically paternalistic views of human sexuality and reproductive rights. Overtly racist comments are made by Republican leaders (usually unelected leaders) on a regular basis. And, finally, the party has an uneasy relationship with science since much of its base rejects basic scientific theories like of evolution, plate tectonics, and climate change.

All of this has resulted in a deeply divided political culture that is rife with the types of disagreements that cannot be resolved by debate and compromise. When Teddy Kennedy came to the Senate, the two parties were internally split on both regional and ideological matters.

“When Kennedy came, both political parties in the Senate were internally divided,” said Don Ritchie, the associate Senate historian. “There were as many Eisenhower Republicans as Goldwater Republicans. There were more liberal Democrats but a sizable number of conservative Democrats. There was never a party line vote on anything. There were ideological coalitions rather than partisan coalitions.”

The Senate still has regional coalitions on many votes, but that is the only area where it still has split votes. It’s impossible to do almost anything in the Senate without filing for cloture (the 60 vote requirement).

In 1963, Mr. Kennedy’s first full year in the Senate, the leaders filed just one “cloture motion,” Senate parlance for the procedure that can end a filibuster by cutting off debate. Last year, 50 cloture motions were filed.

The emergence of CSPAN and the 24-hour news cycle have certainly contributed to the breakdown in comity in our political arena. But the failure of the Republican Party to attract anyone but white (usually male) Christians into their coalition is the primary driver of our divisions today. There’s nothing wrong with white men from a Christian background, but there is something wrong with a party that is made up almost exclusively of them. When you add to this insularity a tendency to reject the most basic and important theories in geology, biology, and climatology, you have a party that is incapable of being an honest partner in setting fair and sensible policies for our nation.

In other words, the GOP is broken. That the Senate is also broken is mainly just a derivative outcome.