If they play their politics right, they should introduce the PACE Act after Comprehensive Immigration Reform. Just in case the latter is killed in the House or Conference, they could try to sneak the immigration related proposals along with the other recommendations in the House. Of course, this is assuming that PACE will not have much resistance in the House.
A companion piece of legistlation to S.2198 will be introduced in the House in a few weeks and hopefully similar provisions will exist in the House version too. It will be interesting to watch which provisions are immigration-related.
Politics is fascinating. Who could have thought of introducing Sen. Hagel's proposals in an "Energy" bill.