Today's installment of campaign-related news items from across the country.
* In the new NBC News/Wall Street Journal/Marist polls, Hillary Clinton is ahead in Iowa (48% to 45%); she has a much bigger lead in South Carolina (64% to 27%); but Bernie Sanders is still well ahead in New Hampshire (57% to 38%).
* Bernie Sanders, who will turn 75 years old by Election Day, will reportedly release his medical records later today. This meets a vow from the campaign to disclose the materials before the Iowa caucuses.
* Political insiders are absolutely convinced that Marco Rubio would be a strong general-election candidate for Republicans, while Donald Trump would be a weak one. Republican voters, meanwhile, are equally convinced the exact opposite is true, at least according to the latest Washington Post/ABC News poll.
* Congratulations, John Kasich, you're now relevant enough to attack. A secretive far-right group called the American Future Fund, which does not disclose its donors, is launching a $1 million ad campaign against the Ohio governor, telling New Hampshire Republicans Kasich is an "Obama Republican," not a conservative or a moderate.
* Speaking of New Hampshire, Chris Christie is going after Marco Rubio with increasing vigor, telling Boston Herald Radio yesterday that the Floridian is "a 44-year-old first-term senator who's never accomplished anything."
* Politico reports that Rand Paul is under renewed pressure from GOP officials to shift his focus from his struggling presidential campaign to his Senate re-election campaign in Kentucky.
* Rep. Mark Meadows (R-N.C.), perhaps best known for role in trying to oust then-Speaker John Boehner, officially endorsed Ted Cruz on Fox News last night. Meadows is reportedly headed to Iowa to campaign for the Texas senator.
* Three days after the South Carolina Republican primary are the Nevada GOP's caucuses, which have been woefully under-polled. Jeb Bush will travel to Nevada on Monday -- the day of the Iowa caucuses.
* The level of U.S. support for a Michael Bloomberg presidential candidacy is unclear, but News Corp chief Rupert Murdoch seems to support the idea.
* And speaking of the former New York City mayor, Kathy Kiely, the Washington news director for Bloomberg Politics, resigned yesterday over concerns related to coverage of Michael Bloomberg's possible campaign.