The case goes like this: In the core red states that will decide Senate control, there are very few genuinely persuadable voters left. Base turnout will be decisive. Any action by Obama risks further inflaming the GOP base at a time when the fading of Obamacare as a major issue, and the lack of 2010′s seismic levels of rage, could mean core GOP voters aren’t quite as engaged as during the 2010 shellacking.

Meanwhile, Dem hopes for survival rest heavily on turning out the unmarried women who are increasingly key to the Dem coalition but sit out midterms. The way to move them is with a message relentlessly focused on women’s economic issues. Any move that allows Republicans to argue Dems are focused on giving jobs to illegal immigrants — however demagogic — risks muddling that message in the minds of voters who are already suffering from economic insecurity. While some argue acting would rev up core Dem groups, Latinos are not a major factor in these races and it might not have any such impact on these unmarried red state women.