Pendulums swing in politics, and not every election will be a Democratic wave. However, certain demographic trends seen in this year’s election have to be discouraging for Republicans.

Before the election, some Republicans were confident about John McCain’s chances, in part because they expected a “Bradley effect” to be skewing polls toward Barack Obama. That is, they thought large numbers of white people might be lying to pollsters about their intention to vote for Obama. Polling experts like Sam Wang and Nate Silver and Mark Blumenthal predicted weeks ago that there would be no Bradley effect, and Tuesday’s results showed they were right.

Not only that, Obama did better among white men and white voters generally than John Kerry did four years ago. Obama’s relatively strong performance among whites increased his national popular vote lead and swung states like Indiana (which had not voted Democratic for president since 1964) into his column.

NBC’s Chuck Todd has drawn attention to Obama’s strong showing among college-educated whites in particular:

Our final NBC/WSJ poll before the election showed that Obama had a three-legged stool of support that contributed to his lead over McCain — African Americans, Hispanics, and 18-29 year olds. And that poll (and others like it) proved to be right. Obama won African Americans, 95%-4%; Hispanics, 66%-32%; and 18-29 year olds, 66%-32%. But Obama had one extra bit of support that turned a three-legged stool into a four-legged chair: college-educated whites. McCain narrowly beat him here, 51%-47%, which helped reverse a 17-point deficit Kerry had with all whites in 2004 to the 12-point deficit Obama had last night. And it’s what helped Obama do so well in suburban counties like the ones above in Pennsylvania or the ones in the I-4 corridor of Florida or the ones in Northern Virginia. That’s the difference, folks, between losing an election and winning one.

Obama also more than doubled Kerry’s winning margin among Latino voters. Nationally, he took about 67 percent of the Latino vote. McCain, who was supposed to be a relatively appealing Republican with this demographic, won just 31 percent of their votes. To make matters worse for the GOP, “the number of Latinos who went to the polls increased by nearly 25 percent over 2004.”

In part because of Latino voters, states like New Mexico and Nevada, which were very close in 2004, went to Obama by more than 10 points.

Now look at the charts about the youth vote (aged 18-29) in this post by Mike Connery. Young voters split almost evenly between Bush and Gore. In 2004, they went for Kerry by a 9-point margin. In 2006, they went for Democratic Congressional candidates by a 22-point margin. This year, they went for Obama over McCain by a ridiculous 34-point margin (66 percent for Obama, 32 percent for McCain).

Scroll down this page a little to the graph showing what the electoral map would look like if only 18-29 year olds were voting. McCain would win just eight states for 57 electoral votes and be tied in Arkansas. Also,

Sixty percent of all new voters this year were under age 30, according to a report by Tuft’s Tisch College Center for Information and Research on Civic Learning and Engagement, or CIRCLE.

The Republicans better figure out a way to reverse this trend quickly, because

Many academic studies show that if a voter votes for the same party in three consecutive elections they disproportionately carry that political identification with them for the rest of their lives.

Voters between the ages of 18 and 29 are a large cohort, because they are mostly children of the Baby Boomers. They have now voted overwhelmingly Democratic in two consecutive elections (2006 and 2008).

Finally, let’s not forget about women voters. They make up more than half of the national electorate, and they went for Obama by 55 percent to 43 percent. Incredibly, 70 percent of unmarried women voters supported Obama. In Ohio, Obama got 54 percent of the women’s vote, and in Pennsylvania he got 60 percent of the women’s vote.

If I were a Republican anywhere, I would be depressed by these numbers.

In the next day or so, I will write about the deep hole Iowa Republicans are in.

UPDATE: If I were a Republican, I would probably drop most of the social issues rhetoric and stick to big government and taxes. However, via Todd Beeton at MyDD I learned that exit poll data don’t show this as a promising path either:

   View of Government

   Should do more 51

   Doing too much 43

   Will your taxes go up if Obama wins?

   Yes 71

   No 27

   Among voters making $200,000 or more

   Obama 52

   McCain 48

UPDATE 2: Paul Rosenberg asserts that the GOP [is] Set to Drive Off a Cliff. Click the link to view charts from a new Democracy Corps report, showing that the electorate as a whole thinks the Republicans lost the 2006 and 2008 elections because they were too conservative, and that the GOP needs to appeal more to moderates to win.

Meanwhile, the subset of Republican respondents in the Democracy Corps survey said the Republicans lost in 2006 and 2008 because they were not conservative enough.

Similarly, this survey yet again shows that McCain’s choice of Sarah Palin hurt him more than any other factor with voters who considered both Obama and McCain. But a Rasmussen survey of Republicans taken after the election showed that most think Palin helped McCain’s candidacy, and favor Palin more than any other likely contender for the 2012 GOP presidential nomination.

If Republicans cannot acknowledge what just happened, they are unlikely to be able to improve their party’s standing.