It has been widely noted that last night’s election represented the largest party shift in the House of Representatives since the election of 1948. But that’s a misleading comparison, as that shift coincided with Truman’s reelection and was part of his electoral mandate.

The correct historical analogy is earlier, and more telling. Prior to last night, the largest midterm shift against the party in power was in 1938, and it effectively ended the New Deal.

FDR was emboldened by his 1936 landslide reelection to expand his agenda and consolidate his control of government. This phase of the New Deal proposed the reform of the judiciary (his “court-packing” plan) and a controversial government reorganization bill that would have vastly expanded the power of the presidency. In response to the recession of 1937, FDR launched a campaign against the wealthy, abandoned his efforts to balance the budget and turned to stimulus spending, which was being pushed by some economist named Keynes. (It was $5 billion in 1938, or over $63 billion in current dollars.) Congress also passed the Fair Labor Standards Act, establishing a national minimum wage.

As a result of all this, in the midterm following, Republicans picked up 80 seats in the House and six in the Senate.

Democrats still controlled Congress and FDR went on to be reelected in 1940, but the expanding course of the New Deal was over.

Last night’s election effectively stopped the Obama administration’s attempt to revive expansionary progressive government. The fact that it reversed the control of the House, and happened so quickly, confirms that there has not been a political realignment like FDR achieved in 1936, which made Democratic losses in 1938 less disastrous. But the 2010 election, also like 1938, does not yet mean the national course has changed, that progressive successes have been reversed or that a liberal president might not go on to be reelected.

As Churchill said after avoiding absolute defeat at Dunkirk: “This is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.”

— Matthew Spalding is director of the Heritage Foundation’s B. Kenneth Simon Center for American Studies.