Updated 5:24 p.m. ET

Ohio Gov. John Kasich is the latest big-name Republican to endorse Mitt Romney for president.

Kasich and his lieutenant governor, Mary Taylor, gave their formal support to Romney today, as the likely GOP nominee heads to Ohio for a campaign speech.

Kasich, a former House Budget Committee Chairman in the 1990s, has seen his polling numbers dip because of his support for a law limiting collective bargaining rights for public employees.

Kasich previously said he would support Haley Barbour for president, but the former Mississippi governor and ex-Republican National Committee chairman decided not to run.

Romney has been locking up endorsements since rival Rick Santorum withdrew last week.

Ohio Rep. Jim Jordan, chairman of an influential group of House conservatives, told Deirdre Shesgreen of the Gannett Washington Bureau that he's also backing Romney.