By looking at the data going back to 1992, strong partisans have voted for their party's presidential candidate more than of the time in every election

90%. Strong partisans follow the party line and vote for the person that they are told to vote for by the party leadership. This can work out or it can be disastrous. The election of Hillary Clinton is an example of choosing the person that the party leadership wants and it not working out. It ended up angering voters. On the alternate end the Election of Donald Trump would be how it could work out. The Republican Party was initially hesitant and against him. However, they saw the crowds and recognized the benefit of riding the fandom. They had to convince some of their strong partisans to vote for him. He didn't originally fit the "Republican" mold.