A new Gallup poll shows a slight shift in party identification in favor of the GOP, giving them the edge over Democrats for the first time in 8 years.

Since the Republican Party's strong showing on Election Day last month, Americans' political allegiances have shifted toward the GOP. Prior to the elections, 43% of Americans identified as Democrats or leaned toward the Democratic Party, while 39% identified as or leaned Republican. Since then, Republicans have opened up a slight advantage, 42% to 41%, representing a net shift of five percentage points in the partisanship gap.

The pre-election results are based on Gallup Daily tracking interviews with 17,259 U.S. adults, conducted between Oct. 1 and Nov. 4. The post-election interviews are based on 12,671 interviews conducted Nov. 5-30.

There have been similar "bandwagon" effects for the winning party in the past, including after the 1994 and 2002 midterm elections, when Republicans benefited, and after the 2006 election, when Democrats made gains.

The most dramatic shift occurred after the 1994 midterms, in which Republicans picked up more than 50 seats in the House of Representatives to gain a majority in that chamber for the first time in 40 years. Before the 1994 elections, Democrats enjoyed a four-point advantage in party affiliation, but after the GOP wave, Republicans emerged with a 12-point margin, for a total shift of 16 points in the gap.

In 2002, Republicans capitalized on the popularity of George W. Bush to accomplish the rare feat of having the president's party gain seats in Congress in a midterm election. After that strong showing, partisanship moved from a five-point Democratic edge to a four-point Republican margin.

Four years later, with Bush's job approval rating stuck below 40%, Democrats gained control of both houses of Congress. An already strong Democratic partisanship advantage of 14 points swelled to 22 points after the election.

Not every "wave" election has produced a distinct shift in a party's advantage. The 1998 and 2010 midterms were also notable for their outcomes, but did not produce any apparent change in Americans' basic party loyalties. In 1998, Democrats gained seats in the House even with a Democratic president in office. In 2010, Republicans gained a net of 63 seats in the House to win back control of that chamber. That year, the shifts in party allegiances seemed to be in place before the election, with the smallest Democratic edge seen in any recent midterm year.

The shift in party ID was small for a wave election, which may show that the country has become about as polarized as it's going to get. Every election there are fewer and fewer "persuadables" in the electorate as voters become set in their preferences. It's believed that Republicans are about at their limit of 247 House members, thanks to gerrymandering. That may indicate a plateau has been reached in party ID for Republicans. Democrats may continue to lose support, however, so their margin may widen between now and 2016.