In the 2010 Midterm elections, the Republicans took control of the House, but Democrats still have power in the senate and white house. Barack Obama almost certainly will be the 2012 Democratic candidate and Nancy Pelosi prepares to run for House Minority Leader.
The Democratic Party won the 2008 election making Barack Obama the first African-American president. With Nancy Pelosi the speaker of the house and Democratic control in Congress the democrats were able to push things such as the Health Care Reform Bill and the Economic Stimulus.
George W. Bush came into white house after defeating Al Gore by winning the electoral vote. While in office, Bush had some tough issues such as 9/11, Hurricane Katrina and a failing economy. He had a 2 term presidency and with republicans both leading the house & senate was able to get things done.
The Democrats went back into the White House when Bill Clinton beat George H.W. Bush in '92 and Bob Dole in '96 and people believed that a new, more vitalized democrat party was emerging. But, the democrats failed to gain power in Congress in both the '96 and '98 elections.
In the 1990's Republican party was able to control both the house and the senate while Clinton and George H.W. Bush were in office. In the 90's the Republican party with Newt Gingerich leading them, came up with the Contract with America.
In the 70s the Democrats started to come back together, and had a sold hold in the House of Representatives and in 1976 Jimmy Carter, a democrat from Georgia was able to get the Democrats back into the White House.
In the Early 1900's there was a resurgence of the republican party with victories with Theodore Roosevelt and with Herbert Hoover elected president in 1928 and carrying some of the old confederacy votes.