There is a long history of bipartisan cooperation between liberals and conservatives in passing important legislation that benefited the nation. A perfect example is liberal Democrat Lyndon Johnson’s civil rights legislation in the mid 1960s.
Johnson pushed for civil rights legislation to help African Americans gain legal equality. One of the greatest obstacles to Johnson’s plans were members of his own party. At that time, segregationist Southern Democrats made up a sizable number of the Democratic Party and they threatened to filibuster civil rights legislation in the Senate. In order to overcome a filibuster, President Johnson needed the support of moderate and conservative Republicans to join with liberal Democrats. The key to this support was the Senate Minority Leader, a conservative Republican from Illinois named Everett Dirksen.
Dirksen had supported civil rights legislation during his time in the House of Representatives, voting for anti-poll tax and anti-lynching measures. Dirksen worked with Hubert Humphrey, Mike Mansfield and other Democratic leaders in breaking the Southern Democrat filibusters to pass the Civil Rights Act of 1964 and the Voting Rights Act of 1965.
Here is a video from the LBJ Library of a telephone recording of President Lyndon Johnson and Senator Everett Dirksen on June 23, 1964 where Johnson asks for Republican support for an Excise Tax Bill and Dirksen talks about his actions to help support the 1964 Civil Rights Bill.