A flat tax-based campaign didn't help Steve Forbes win the GOP nomination, but, with his endorsement of Rick Perry, he's betting the Texas governor can do a bit better. The announcement follows a few days of elation from Forbes after Perry decided to shake up his campaign by introducing his own risky proposal. "It's finally coming to pass," Forbes said of his pet tax plan last week. As CNN reports, the Perry campaign unveiled the officially-minted endorsement on Monday: "I am honored to have Steve's endorsement of my candidacy for president." It arrives a day before Perry will be introducing the full proposal to be picked over by pundits like Herman Cain's 9-9-9 plan. So maybe Forbes will be joining him in explaining its simplicity tomorrow.