Bill Hobbs has got it figured here that "Gov. Bredesen, a Democrat, is pandering to the pro-abortion segment of his base, by fulminating against the 'Choose Life' license plate, while avoiding a veto that would anger pro-life Tennesseans who voted for him."
I agree with that, as in this earlier post comparing Bredesen with Governor Warner.
Before getting to that point, Bill Hobbs said also that a lawsuit over the "Choose Life" license plate "would fail - as it has in other states." One state where that kind of claim did not fail is South Carolina, where Judge Bertelsman (from Kentucky) ruled the license plate was unconstitutional in Planned Parenthood v. Rose, 236 F. Supp.2d 564 (D.S.C. 2002), and that is the case that Governor Warner cited here.