Political winds of change are blowing and, for now, coming from the right. Since August, they have been gusting at hurricane force. The five elections that have taken place since then give an indication of the storm’s strength and the impact it could have if it hits Washington unabated in November.

Summer proved to be America’s season of discontent, with August a seeming tipping point. Five elections of national import have taken place since that time: House races in California and New York, gubernatorial races in Virginia and New Jersey, and a special Senate election in Massachusetts. Despite differing outcomes—Democrats won two of the three—the table below shows a pronounced trend.

*Conservative Party candidate total

The outcomes are significant because the five races took place in different regions, with very differing electorates, and with none in dark “red states.” Still, Democrats averaged a 10.8 percent decline from the totals reached by Obama in November 2008. Removing the outlier of N.Y.-23, the average jumps to 12.8 percent. Conservatives have benefited by an almost equal amount.

The Democratic drop and the conservative uptick combine for a massive swing. In political parlance, a “safe seat” is generally one held by a threshold of 60 percent or greater. The swing of roughly 20 percentage points seen since August potentially endangers all but safe seats. The possible impact of such “jeopardization” can be quickly enumerated.

In the House, 57 incumbent Democrats in their last election did not attain vote percentages large enough to offset such a swing. Another ten incumbents have announced they will not seek re-election this November—thus removing their large incumbency advantage. Finally, there are five incumbents who won their seats in special elections, giving them less than a full term to build a connection with their constituents.

In the Senate, where only 18 Democrat-held seats face election this November, the impact is muted, but similar. Five Senators in their last election failed to attain the vote percentages needed to offset the “post-August five” decline. Three more seats will be open and five more are held by appointed Senators who have never faced their constituents.

Even if just half these races saw a replay of the “post-August five” phenomena, the impact would be substantial. Republicans would gain 36 House and six Senate seats—bringing their totals to 214 in the House and 47 in the Senate. Neither are majorities, but both are only just short of them.

And there is no reason to believe necessarily that the “post-August five” trend would not continue beyond November. The electorate cannot be presumed to have simply “gotten things out of its system.” It will take events to have changed first and for every event a negative change is as plausible as a positive one.

Any reversals in 2010 are going to be very hard for Democrats to recoup—particularly in the Senate. While House seats are re-elected every two years, Senators are re-elected every six years. In the four years following 2010, 44 Democrat Senate seats—three-quarters of Democrats’ current total—will be up for re-election.

Certainly conservatives face their own challenges, which could buffer the effects of the prevailing winds. The Republican Party presents its own difficulties—the anti-incumbency aspect of the “post-August five” outcomes could affect their open and low-margin seats too. And the example of the N.Y.-23 special election shows dramatically how party politics can affect adversely conservatism’s welling strength.

To paraphrase former Speaker Tip O’Neill, all elections are local. They are decided in the end between two candidates. Only by looking at the conditions in each race, can you get a true feel for outcomes. However, the same was true in each of the “post-August five” races, yet the outcome was virtually the same in each one. That level of similarity, despite the local dissimilarities, starts to give clarity to potential aggregate outcomes.

The wind of change has been blowing strong since August. Right now, the Democrats appear to be heading into it and Republicans to have it at their backs. And any ship, even a partisan one, is far more easily navigated riding the wind than fighting it.

J.T. Young served in the Department of Treasury and the Office of Management and Budget from 2001—2004 and as a Congressional staff member from 1987-2000.