Since the last debate, the three Democratic front-runners remain the same, but their current podium order has begun to shift. Senator Elizabeth Warren, former Vice President Joe Biden and Senator Bernie Sanders enter the stage tonight with new political shots and chasers: WARREN — Elizabeth Warren will take the debate stage tonight with more momentum than she’s had at any other point in the race so far, according to CBS News Campaign Reporter Zak Hudak. She started the day by releasing a campaign finance reform plan that included new promises such as not taking donations over $200 from tech or bank executives, but it focused mostly on measures she’s already suggested or promises she’s made, like not holding large dollar fundraisers.The plan could be seen as preparation for a counter punch to potential attacks in the debate tonight. South Bend Mayor Pete Buttigieg, for example, has been contrasting his “Medicare for All Who Want It” plan with Warren’s support for Bernie Sanders’ “Medicare for All” plan. BIDEN — It has been 26 days since the first reports of President Trump’s request to a foreign government to investigate Biden and his son, Hunter, says CBS News Campaign Reporter Bo Erickson. Biden has hit back hard on the…