The Proposition 8 trial is ending with a bit of a bang.

After an afternoon that more resembled the elbow throwing of the political campaign over gay marriage than the placid decorum of a legal proceeding, Chief U.S. District Judge Vaughn Walker tacked on an extra day of the trial as the Proposition 8 defense’s second and final witness could not finish his testimony Tuesday.

That witness, David Blankenhorn, spent several hours essentially arguing with David Boies, one of the prominent lawyers representing same-sex couples in their bid to overturn California’s ban on their right to marry. The exchanges were openly bitter, and underscored the controversial nature of Blankenhorn’s thesis: that procreation is the central purpose of marriage, and that gay marriage will lead to the downfall of traditional heterosexual marriage.

“If you change the definition of the “thing,” Blankenhorn said of marriage, “it is hard to imagine how it wouldn’t have an impact on the ‘thing.’ ”

Blankenhorn, president of the Institute for American Values, is one of two witnesses called by lawyers defending Proposition 8, the 2008 voter-approved law that restored the state’s ban on same-sex marriage. Earlier Tuesday, Kenneth Miller, a Claremont McKenna political science professor, finished up his stay on the stand, testifying that gays and lesbians are gaining in political power.

Read the rest of Howard Mintz’s San Jose Mercury article here.