Political parties may often practice coalition policy making by cooperating with their counterparts to ensure legislative organization - creating an environment of order when it comes to political debates inside the House of Representatives and the Senate -, and to appeal to the electorate during political campaigns.
Parties long for these practices in order to pursue their own interests, and procure they get the most value out of the coalition. This is done knowing that voters prefer representatives who impulse cooperation and diversity, rather than those who blatantly create disputes and publicly stand for their own goals.