Today’s installment of campaign-related news items from across the country.

* Republican Sen. Markwayne Mullin this morning threw his support behind Donald Trump’s 2024 presidential campaign. The Oklahoman is the fifth sitting GOP senator to back the former president’s comeback bid.

* Speaking of Trump’s 2024 bid, Jason Miller, a veteran of Trump’s 2016 and 2020 campaigns, is rejoining the Republican’s operation. As NBC News reported, the move means Miller is stepping down as the CEO of something called GETTR, which is apparently a right-wing social media site that was intended to rival Twitter.

* Here’s a revelation that we’ll likely be hearing more about in the coming months: When Gov. Ron DeSantis first ran for Congress in 2012, the Florida Republican expressed support for privatizing Medicare and Social Security.

* Ahead of former Vice President Mike Pence’s likely national campaign, the Indiana Republican’s advocacy group is launching a new ad buy in Iowa, home to the GOP’s first presidential nominating contest. The message is focused on Pence’s opposition to support for transgender students.

* The featured speaker at the Conservative Political Action Conference’s Ronald Reagan Dinner next month will be failed gubernatorial candidate Kari Lake. CPAC organizers announced the decision yesterday.

* And NBC News reported this morning that the Federal Election Commission is issuing an ultimatum to Rep. George Santos, telling the New York Republican “he has 35 days to declare whether his recent fundraising means he’s running for re-election or not.”