Read this and answer the question. If the question is unanswerable, say "unanswerable".

In 1996, Kerry faced a difficult re-election fight against Governor William Weld, a popular Republican incumbent who had been re-elected in 1994 with 71% of the vote. The race was covered nationwide as one of the most closely watched Senate races that year. Kerry and Weld held several debates and negotiated a campaign spending cap of $6.9 million at Kerry's Beacon Hill townhouse. Both candidates spent more than the cap, with each camp accusing the other of being first to break the agreement. During the campaign, Kerry spoke briefly at the 1996 Democratic National Convention. Kerry won re-election with 53 percent to Weld's 45 percent.

Who ran against Kerry in 1996?
William Weld