Reflecting on the repeated drubbings they have doled out since the process began six months ago, advisers for Republican presidential candidate Marco Rubio confirmed Wednesday they are secretly enjoying totally destroying him during their practice debates. Campaign staffers, who admitted to privately referring to the Florida senator as a human punching bag, acknowledged the immense level of satisfaction they derive from dominating Rubio when standing in as his Republican opponents, be it by systematically dismantling his every argument, exposing his limited knowledge of labor relations and environmental policy, or simply outshining him as an orator. Getting up there and completely embarrassing him in front of the rest of the campaign leadership is easily the best part of my day, said senior strategist Grant Hutchinson, admitting that he would always fondly remember their first mock debate, when he immediately wiped the smug look of self-assurance off Rubios face with a single barbed question. Last week, I challenged him to name one reason why we should trade with Saudi Arabia but not Cuba, and he started fumbling over his words and grasping at straws. I made it quite clear that he didnt know what the hell he was talking about, and he just had to stand there quietly and take it. God, it felt so damn good, he added. While originally hoping to help Rubio polish his speaking points and delivery ahead of the nationally televised events, aides said they now attend practice sessions largely to watch the candidate become visibly frustrated at their well-articulated counterarguments on subjects ranging from U.S. oil importation to health care. Advisers confirmed that the most difficult part of their job is simply keeping a straight face when Rubio flashes his deer-in-the-headlights look each time his ignorance of a particular topic is revealed or he begins to lose his train of thought. Saying the brutal 90-minute sessions always end too soon, staff members conceded that they frequently go out for dinner together afterwards for a chance to share laughs about the days exchanges and relive the abuse they forced Rubio to endure. Campaign sources confirmed they also use their outings to trade tips on how best to badger and antagonize the candidate, reportedly egging one another on to humiliate him in upcoming exercises by taking advantage of his overeagerness and inability to think on his feet. I can tell all the practice is starting to wear on him, especially after I twisted the knife on reproductive rights during yesterdays prep session, said staffer Aaron Merchant, who giddily recalled how he left the overwhelmed candidate sighing and stammering for at least 20 seconds following a question on paid maternity leave. Eventually, I decided I should lay off him for a while to help build his confidence back up. I stopped rebutting each of his statements and correcting his factual errors, and after a few minutes he really started to look comfortable. Which made it that much sweeter when I hit him with a pointed one-liner about his inconsistent position on national security spending and cut him right back down again, he added, smiling. You shouldve seen it; he went as white as a sheet! Using Wednesdays Republican primary debate in Colorado as an excuse, campaign members told reporters theyve recently been running Rubio through two, sometimes three mock debates a day, solely for the additional opportunities to watch him squirm. Sources added that there is often considerable infighting among staff members over who will have the chance to stand in as Rubios opponent each morning, as well as daily side bets regarding how long it will take before the candidate begins nervously sweating through his shirt. A couple days ago, we had to cancel a debate prep session after a campaign stop in New Hampshire went long, which was really disappointing for us, said staffer Lisa Wilson, noting how Rubio, on the other hand, appeared visibly relieved and upbeat for the remainder of that day. Wed really been looking forward to raking him over the coals for the immigration bill he sponsored, but we couldnt. We made sure to schedule a double session the next day though, and, boy, did we ever tear him to shreds. Honest to God, there was a point there where I thought he might start crying. At this point, were working as hard as we can around the clock to help him win the nomination, she added. That way, we can lay into him even harder ahead of the general election debates. 