Mormons for Obama would definitely disagree with that assessment of their personal righteousness. So would all LDS General Authorities for that matter.
Even though I personally have not yet selected the candidate who will get my vote, I fully support the rights of any person, LDS or not, to make that decision without casting aspersions on integrity or devotion to God. I'm grateful that our Church leaders make it absolutely clear that there is no one right party affiliation for Latter-day Saints or any particular candidate(s) to vote into office. A hearty amen to their encouragement of political participation for all members (where possible) and emphasis on civil and respectful discussion.
Witness an example of political vituperation over at Bandanamom's blog, where an anonymous commenter equates her support of Obama with a complete abandonment of the prophets and the gospel of Jesus Christ. Any opposition to anon's point of view (or choice of words) is summarily dismissed by the superior knowledge of eternal truth anon possesses.
Even at self-described conservative Jettboy 's Straight and Narrow blog, discussions of policy disagreements, why he feels most Mormons won't vote for Barack Obama, and comments opposing the positions he puts forth didn't yield any such personal attacks.
Similarly civil discussions all over the 'nacle have me wondering--why would someone use political criteria to judge faithfulness to covenants and Christ? Is it a lack of confidence in one's position, feeling threatened by a different point of view? Is it pride? Delusions of righteous grandeur? Help me understand.