In a move that had been telegraphed for weeks, the Club for Growth on Monday formally endorsed former state Speaker Marco Rubio (R) in Florida’s Senate primary, setting up a marquee showdown with national GOP leaders, who are backing Gov. Charlie Crist.Club President Chris Chocola called Rubio a “proven champion of economic liberty— in a statement, which came just days after the group announced it would release a television ad attacking Crist for endorsing President Barack Obama’s economic stimulus plan earlier this year.Crist, who has already been endorsed by the National Republican Senatorial Committee, “has repeatedly joined with big government liberals on major economic issues facing America today— Chocola said Monday.The powerful anti-tax group is coming off a high-profile battle with the National Republican Congressional Committee in the special election in New York’s 23rd district.In that race, the Club was instrumental in undermining the candidacy of moderate state Assemblywoman Dede Scozzafava (R), who was backed by the national party before she ended her bid. The club’s preferred candidate, Conservative Party nominee Doug Hoffman, was defeated in the special election Tuesday night.The group, which made its endorsement of Rubio on Monday through its political action committee, said that either Rubio or Crist would be able to beat Rep. Kendrick Meek (D) in the general election. “The Club for Growth PAC has spent months studying this race, and we have concluded that either Charlie Crist or Marco Rubio would be heavily favored to win next November against likely Democratic nominee Kendrick Meek,— Chocola said. “The only question now is what kind of Republican will Florida send to Washington next year: a pro-growth Republican with a record of fiscal conservatism or a big-government Republican with a record of tax increases?—