http://www.mrlincolnandfreedom.org/inside.asp?ID=9&subjectID=2
1848 Campaign
Before the end of the 1847-1848 congressional session, Mr. Lincoln commented on the upcoming presidential contest and slavery on the House floor. "Our democratic friends seem to be in great distress because they think our candidate for the President don't suit us. Most of them can not find out that Gen: Taylor has any principles at all; some, however, have discovered that he has one, but that one is entirely wrong. This one principle, is his position on the veto power...."1 Later in his speech, Congressman Lincoln said: " I have said Gen: Taylors position is as well defined, as is that of Gen: Cass. In saying this I admit I do not certainly know what he would do on the Wilmot Proviso.
I am a Northern man, or rather a Western free state man, with a constituency I believe to be, and with personal feelings I know to be, against the extension of slavery. As such, and with what information I have, I hope and believe, Gen: Taylor, if elected, would not veto the Proviso. But I do not know it. Yet, if I knew he would, I still would vote for him. I should do so, because, in my judgment, his election alone, can defeat Gen: Cass; and because, should slavery thereby go to the territory we now have, just so much will certainly happen by the election of Cass; and, in addition, a course of policy, leading to new wars, new acquisitions of territory and still further extensions of slavery. One of the two is to be President; which is preferable?"2