Tom Davis, a former chairman of the National Republican Congressional Committee who represented Virginia’s 11th District in the U.S. House, is chairman of the Republican Main Street Partnership.

Much has been written in recent months about the future of the Republican Party, as “conservative” Rick Santorum proved popular among many primary voters against “centrist” Mitt Romney. This centrist vs. conservative meme is an oversimplification of the primary fight between Romney and Santorum, but it is not new. For years, the media have been fascinated with perceived intraparty ideological battles.

In April 2009, Sen. Arlen Specter (Pa.) left the Republican Party for the Democratic Party, giving President Obama a filibuster-proof majority in that chamber. Specter said that the GOP had left him behind, that it was Republicans who had changed — not he.

But Specter’s decision was as much about political survival as about his beliefs. In his announcement, Specter conceded that he was unlikely to win a Republican primary and said that he was “unwilling” to have his “29-year record judged by the Pennsylvania Republican primary electorate.”

Yet more mainstream media reports focused on what Specter’s exit supposedly said about the GOP than on his electoral calculation. Journalists ate up Specter’s argument and likened centrist Republicans to dinosaurs — politically extinct relics.

More recently, the announcement by Sen. Olympia Snowe (R-Maine) that she would not seek a fourth term sparked claims of “proof” that centrist Republicans are gone.

To paraphrase Mark Twain, reports of the demise of centrist Republicans are greatly exaggerated. Olympia Snowe is no Arlen Specter, and centrist Republicans are alive and well. By “centrists,” I do not necessarily mean “moderates” but refer instead to members who are willing to work across the aisle to find common ground with partisan opponents to achieve tangible results. There are indeed still members of Congress who recognize that the perfect should not be the enemy of the good and that some incremental change can be preferable to no change.

The Republican Party has certainly become more conservative, in the same way that the Democratic Party has become more liberal. Centrists are pragmatists who are willing to compromise to get things done and work across party lines. Working across the aisle wasn’t as difficult in previous Congresses, because there were Republicans who held views to the left of some Democrats, and vice versa. Compromise wasn’t always needed because it’s not compromise if the position is already something you support. In today’s political environment, however, compromise is a prerequisite to accomplishing anything — one need look no further than the votes to avoid the U.S. credit default last summer, to avoid a government shutdown or to prevent taxes from being raised on working families.

Centrist Republicans make up a critical voting bloc in the House. In the wake of the 2010 midterms, the organization that I head — the Republican Main Street Partnership — now has a record 57 members in the House and Senate.

Without question, centrists in both parties face intense pressure not to act like centrists. It takes political courage and skill to navigate this minefield. The pressures faced by centrists in both parties are the result of several macro factors:

First, campaign finance laws, as well-intentioned as they may have been, have pushed money away from the political parties — centering forces — and out to ideological interest groups. Politicians face more pressure to please these extreme interests.

Second, balkanized media. It is not just that liberals have MSNBC and the Huffington Post and that conservatives have Fox News; the issue is greater than consuming news through an ideological lens. With few filters on talk radio, Internet sites or the 24/7 cable news shows, those debating the issues often can’t agree on the same set of facts.

Third, the ideological sorting of the parties. Gone are the days of conservative Democrats and liberal Republicans. Now the most liberal Republican in the Senate is more conservative than the most conservative Democrat. This ideological sorting has been reinforced by gerrymandered House districts that leave fewer truly competitive general-election districts.

These factors affect not just elections but also how the House and Senate do business. For most members in both chambers, the most important election is the primary race, and primary voters are reluctant to reward compromise and eager to reward ideological adherence. The pressures that force candidates out to the ideological extremes in elections also discourage bipartisanship. The same factors leading to an increasingly polarized electorate are creating an increasingly polarized Congress.

Note that Snowe did not say she was leaving the Republican Party because it has become too extreme. Nor did she say she was being forced out. She is not leaving the GOP; she’s leaving the Senate. And poisonous partisanship is a bipartisan problem.

The macro factors cannot be changed by one leader — no single person can create a bipartisan or post-partisan Washington. Real change will not occur until voters in both parties say they won’t stand for this anymore. Given the dismal approval rating of Congress and both political parties, there is reason to believe we are nearing that point. The solution begins with voters sending to Washington more pragmatic, results-oriented members who are willing to compromise to get things done.