Mark Kirk is a racist pig who should not have taken shots at his opponent because her mother was from Thailand. Regardless of where she is from, she is also a member of the DAR, and this is what she was refrecencing in the comment that led to him taking a cheap shot.
No, it is completely immature and inappropriate to try to use a person's heritage against him or her, in any situation but especially in elections. America consists of people from all over the world. Increasingly, other countries are becoming multinational and multicultural. It is very wrong to try to bring any candidate down because of his or her heritage.
Race and heritage should not be fair game during an election, unless the candidate him or herself is campaigning based on heritage. You just don't go there. Duckworth has a long family history of military service to this country, a tradition she continued, and she certainly had the right to mention it. It had nothing to do with her Thai heritage. It wasn't fair game, and Kirk looks like a huge putz.
It's absolutely not fair game to say anything about somebody's heritage. America is a melting pot for a reason. It's just stupid for somebody's nationality to have any negative factor in basically anything in our country. That's what America is, if you have a problem with it then you have a problem with America.