(CNN) House Republicans are at risk of losing several of their members in the midterm elections who are more moderate on the issue of immigration.

Immigration has re-emerged as part of the national conversation in recent weeks as lawmakers in Congress attempted to address the fate of those immigrants affected by the expiring Deferred Action for Childhood Arrivals program. More recently, there's been a national outcry over the Trump administration's 'zero tolerance' policy at the border, which has resulted in thousands of children being separated from their parents.

November's elections offer a golden opportunity for Democrats to take back the House and try to force legislation on immigration. Yet electoral success for Democrats would almost certainly mean losing some of their most likely partners in the Republican caucus.

Take the 23 House Republicans who signed onto a discharge position to force a vote on a bill that would have created a DACA fix. Of this group, 14 are facing competitive re-election battles in November (i.e. not rated as solid GOP) and five are retiring or have already resigned from Congress.

Three of the most prominent members who signed the petition -- Reps. Carlos Curbelo, Will Hurd and Jeff Denham -- are in particularly tough re-election battles. CNN rates those three races as tossups.

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