The May 18 primaries in Pennsylvania and Arkansas are only five days away, with two hotly contested Democratic Senate contests to be decided. In Pennsylvania, Congressman Joe Sestak is closing on the incumbent Arlen Specter, while in Arkansas Senator Blanche Lincoln is trying to fend off Lt. Gov. Bill Halter and prevent the race from going to a runoff on June 8.

The race in Arkansas (which I wrote about in last week’s Nation) has become infused with negativity, with a shadowy front group called Americans for Job Security—reportedly linked to the Chamber of Commerce—relentlessly attacking Halter on the airwaves. Attacks from Lincoln and her allies have put Halter on the defensive, raising his negatives and shifting the focus away from Lincoln’s muddled record on issues like healthcare reform and the bailouts.  Despite all the money spent by labor unions on behalf of Halter, one pro-Halter labor source told me recently, “Lincoln and Americans for Job Security are outspending all of us and the Halter campaign by about 4-1 this week and next.” Yet the attacks could also be backfiring. Arkansas News columnist John Brummett—the most widely read political commentator in the state—recently switched from Lincoln to Halter. His latest column called Lincoln’s campaign “cynically dishonest.”

Lincoln may be all over the map on the issues, but her recent swing to the left on Wall Street reform—a few weeks ago she unexpectedly introduced a much tougher derivatives bill than previously anticipated—has partially undercut Halter’s most effective argument: that Lincoln is a tool of big banks and big business. Nevermind that Lincoln was prepared to introduce a weak compromise bill with Republican Senator Saxby Chambliss before Halter intensified his challenge, or that Senator Maria Cantwell of Washington had to bail Lincoln out during a recent Democratic caucus meeting, according to BusinessWeek. A new report in CQ (subscription-only) speculates that Senate Banking Chairman Chris Dodd plans to to scrap Lincoln’s legislation following Tuesday’s primary. So basically that whole tough-on-Wall-Street thing was just a well-timed political charade.  

In Pennsylvania, Sestak is succeeding by tying Specter to his former Republican allies like George W. Bush and Sarah Palin, and highlighting the fact that Specter opposed Elana Kagan’s nomination as solicitor general and can’t seem to distinguish between Republican and Democratic crowds. The race is now a dead heat.

In Arkansas, the latest poll shows Lincoln up by nine, though she still isn’t above 50 percent, which she needs to get to prevent a runoff. In order to close the gap, Halter should follow Sestak’s lead and remind Democratic voters that Lincoln supported both Bush tax cuts, the war in Iraq, the bankruptcy bill, NAFTA and CAFTA, the original TARP bailout, eliminating the estate tax, and flip-flopped on the public option and Employee Free Choice Act. If Halter wants to win the primary, he can’t let Lincoln’s sudden conversion to progressive populism go unchallenged.