That by supporting their "church buddies," they are also carrying water for McConnell, Boehner & Co. And helping to pass ever more anti-Democratic legislation.
But I probably couldn't be nice in this situation. Like others, I think it's incredibly short-sighted and stupid to vote Repub for this reason. I wouldn't vote for my own mother if she ran as a Republican.
As others have said, I'd at least make sure these people can't pass along party strategy to their church buddies.
Maybe sharing some Gallup data might help:
July 28, 2014 - Religion Remains Strong Marker of Political Identity
Even as overall party identification trends in the U.S. have shifted over the past six and half years, the relationship between religion and party identification has remained consistent. Very religious Americans are more likely to identify with or lean toward the Republican Party and less frequently identify with or lean toward the Democratic Party, compared with those who are moderately or nonreligious.
http://www.gallup.com/poll/174134/religion-remains-strong-marker-political-identity.aspx
June 1, 2009 - Republican Base Heavily White, Conservative, Religious
The Republican Party's constituency is overwhelmingly white -- and the significant majority of those whites are ideologically conservative, while a majority are highly religious, as defined by church attendance. The Democratic Party, on the other hand, has more than three times the percentage of nonwhites among its identifiers as does the GOP. And white Democrats are much more likely to be moderate or liberal than conservative, and are much more likely to be infrequent church attenders rather than frequent church attenders.
http://www.gallup.com/poll/118937/republican-base-heavily-white-conservative-religious.aspx