I grew up in what was widely known as the "solid South," virtually a wholly owned subsidiary of the Democratic Party, whose dominance of the region dated to Reconstruction. When my father ran for governor of Tennessee in 1938, his support came almost entirely from east Tennessee — which had been loyal to the Union! — but the rest of the state was almost hopelessly Democratic. Indeed, his opponent was nominated by the Boss Crump machine in Memphis. Even at 13, I remember being offended by the idea that Republicans could not be elected to a major office in Tennessee.

I've been thinking a lot lately about our party and its future. A president of the opposite party reaching his milestone first 100 days in office; a veteran senator changing parties; the media speculate about whether the Republican Party can win another election. But the Republican Party's core is strong.

One of the few advantages of age is the gift of perspective. In 1964, when I first ran for the U.S. Senate, I was crushed beneath the Lyndon Johnson landslide that not only vanquished Barry Goldwater but also swept in a huge Democratic congressional majority — far exceeding the numbers the Democrats enjoy today.

President Johnson, elected to continue the policies of John F. Kennedy, took an expansive view of his mandate. He gave us his Great Society domestic program and massively escalated the Vietnam War.

This political overreach was evident as early as 1966, and it created a rising tide for every Republican running that year, including a new governor of California named Reagan, a new Texas congressman named Bush and myself — the first Republican ever popularly elected to the Senate from Tennessee.

In other words, after being declared dead in 1964, the Republican Party was resuscitated in 1966 and was victorious at the presidential level in 1968 — with a South that was fast becoming Republican leading the way — and in four of the five presidential elections that followed.

This is a cautionary tale for anyone who believes that Barack Obama's election, or Sen. Arlen Specter's defection, or anything else we may see in the coming weeks and months augurs a permanent shift in American politics.

Things change because things change, not because of any ideological primacy or purity on a particular end of the political spectrum. The American people are, for the most part, highly practical and pragmatic. They like what works, and in a properly functioning political system, two broad-based national parties will offer them reasonable alternatives for what is likely to work best.

The core Republican beliefs in less government, lower taxes, more liberty and greater security in a dangerous world united people as different as Mark Hatfield and Jesse Helms during my years as leader of the Senate. Those same beliefs carried Ronald Reagan into the White House in 1980 and 1984. Those beliefs still have power today. And if the American people perceive overreaching or underachieving in the Obama administration and among its allies in Congress, the Republican way may prove very attractive again in very short order.

It's happened before.

Howard H. Baker Jr., a Republican senator from Tennessee from 1967 to 1985, was White House chief of staff from 1987 to 1988. He wrote this column for The Washington Post.