The ultimate democratic strategy to defeat the proposed constitutional amendment would be to turn the GOPs' oft repeated tactic against them.
To propose a radical amendment that a huge majority of americans support, but that would be completely unacceptable to the far right. Several come to mind
A constitutional amendment barring the state from interfering with a persons inate right to privacy in health decisions.
This amendment would force a rift in the republican party, would force republican state legislators to make a vote that terrifies them. And would at the very least cost the GOP a few state legislative seats as those voting for the amendment would be ostracised by the social conservatives, and those voting against the amendment would face backlash by a majority of women.
A constitutional amendment barring donations to political campaigns by corporations, businesses or other organisations. In addition barring any political campaign or organisation from accepting donations other than from american citizens.
This would clearly delineate the rights corporatism (and some of the democrats) over patriotism and would cut them deeply along the entire political spectrum.
A constitutional amendment barring any person holding or seeking an office from voting or making decisions directly affecting businesses or private individuals in a way disproportionate to the population at large. And barring any person who violates the amendment from holding public office, duty, or employment for life
This would have to be very carefully worded so that it didnt affect average citizens, but rather destroyed the lobbying industry and eliminated the open graft running washington. The implications of this amendment would be stunning and very very popular.
Of course there are probably more. And our ConDems lack the courage, intellect, or desire to do so. But in a democratic party that found its soul again any of these would cut the republicans deeply, and the third, should it pass, would be an achievement along the lines of the Magna Carta or the US Bill of rights.