Final answer:
The comprehensive reform proposed by a bipartisan group of Senators refers to healthcare reform, which has a contentious history in American politics, marked by political opposition and ideological divide.
Step-by-step explanation:
A bipartisan group of Senators have proposed comprehensive healthcare reform. This issue has a long history of provoking intense debate and partisan struggle in American politics. For instance, healthcare reform efforts during President Bill Clinton's administration were met with opposition and failed to pass, which ultimately contributed to a shift in power during the following elections. Similarly, the Affordable Care Act (ACA), passed under President Obama, faced significant resistance and was a point of contention for the Republican Party, despite containing market-based reforms many had previously supported. Such legislative efforts often reflect deeper ideological divides regarding the role of government in providing healthcare, as well as concerns over federal spending and the national debt.