Democrats will have a very difficult time in 2012 hanging onto the US Senate.  They have to defend 23 seats, while Republicans only have to defend 10, thanks to the 2006 midterm victory Democrats celebrated in George W. Bush’s final midterm.  Normally the presence of an incumbent President would provide some coattails for struggling incumbents in down-ticket races, but an analysis of polling by Politico in these upcoming races shows that Barack Obama is providing more of a drag than a boost:

In 2008, President Barack Obama swept into the White House, and Senate Democrats eventually picked up nine seats, giving the new commander in chief the biggest Senate majority in decades.

But as Obama heads into his 2012 reelection campaign, keeping that Senate majority will be a major challenge — and Obama’s weakness at the top of the ticket may be partly to blame.

In every major race next year featuring a Senate Democratic incumbent, Obama is polling worse than the incumbent — in some cases, by a substantial margin — according to publicly released surveys.

For Democrats running for re-election — or as in Tim Kaine’s case, running for an empty seat currently held by a Democratic retiree — the strategy will be to put as much distance as possible from the party’s leader in the White House.  In other words, as one strategist puts it … “go native”:

“Everyone is going to have to ‘go native,’” one Senate Democratic strategist said, speaking on condition of anonymity. “They have to focus on local issues, stay laser-focused on that and not worry about what Obama is doing or saying.” Senate Democrats point to Majority Leader Harry Reid’s 2010 reelection campaign, with which Reid was able to overcome horrific approval ratings and a GOP wave, as their template for victory in other tough races.

Reid lucked into having a weak opponent prone to gaffes, but that’s not going to happen often enough in 2012 to hold onto all but three seats, especially since the other Democrats don’t have Reid’s war chest.  In 2010, Obama wasn’t on the top of the ticket, and could avoid appearing in states with tough races.  In 2012, Democrats up and down the ticket will have to defend Obama, no matter how much they want to “stay local.”  For the most part, that strategy didn’t work in the 2010 midterms anyway, as the election turned into a massive referendum on Obama even without his name on the ticket.

I wrote about this earlier in a couple of speculative posts regarding either a primary challenge to Obama or a withdrawal in favor of Hillary Clinton.  After all, the DNC and other Democrats are looking at the same polling and discovering that Obama may well sink the party’s slim hopes of retaining a majority in one chamber of Congress.  Hillary won the voters in the 2008 primaries that have fled the Democrats over the last two years, and she could woo them back more effectively than Obama.

It’s far too late for her to launch a primary challenge, and Obama’s far too self-confident to consider a withdrawal a la LBJ, but there’s no doubt that Obama is going to sink a number of Senate Democrats in 2012.  The only question is just how many that might be.