On Thursday, Jeb Bush faced one of his most unwavering critics on the issue of immigration. The questions were sharp, the answers were heartfelt, and the result was … inconclusive.

It happened at the National Review Institute’s Ideas Summit in Washington. The conservative magazine has long opposed immigration reform schemes that would amount to an amnesty for those in the United States illegally and an invitation for more to come. When Bush sat down with National Review editor Rich Lowry, the first immigration question had to do with Bush’s rival for the 2016 Republican presidential nomination, Wisconsin Gov. Scott Walker.