HARRISBURG, Pa. -- Tom Ridge isn't ruling out being John McCain's running mate should the Arizona senator win the Republican presidential nomination.

But the former Pennsylvania governor and homeland-security secretary said he doesn't know if McCain is interested and he's not going to bring the subject up with McCain.

When asked how he'd respond if McCain did ask, Ridge replied: "I'll tell you after he asks me."

Ridge says he's backing McCain because of his inclusive approach to politics.

Many GOP fundraisers, party officials and public officeholders in Pennsylvania remain undecided about whom to support.

The state primary is nearly a year away and may come too late in the presidential nominating process to make a difference.