It hasn't taken long for Casey (Jesse Spencer) to get his first taste of dirty politics on Chicago Fire. As his campaign for alderman continues, how much will he have to compromise his own ethics?

"He knows that he's learning as he goes along, but he's still quite idealistic about the whole thing," Spencer tells TVGuide.com. "He's going to have a pretty steep learning curve, I think."

An even bigger problem for Casey may come on the domestic front, however, as the campaign causes problems between him and Dawson (Monica Raymund). "It's going to be much more time than he thinks it is originally," Spencer warns. "It's going to end up causing tension between them in the relationship."

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Adds Raymund: "Dawson's really supportive of Casey throughout this alderman storyline. I think that he starts to doubt his own abilities, and then she's there to instill confidence in him. ... She's always backing him up. ... I think you see him toeing a moral line in terms of what he has to deal with with other people. But what makes Casey so special, what makes him the hero of this show, is that he has his moral code in line. He knows what's right and what's wrong."

Check out the video above to see what else Raymund and Spencer say about how Casey's campaign will affect his and Dawson's relationship:

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