Craig Crawford's Trail Mix

While there is still time for something different, the presidential race in both parties could use a new lineup to keep it interesting.

Before Sen. Hillary Rodham Clinton of New York locks up the Democratic nomination, how about someone other than Sen. Barack Obama getting a shot at the “anything-but-Hillary” nod? Despite months of news media swooning and fundraising triumphs, the Illinois newcomer keeps slipping further behind Clinton in national polls — even after his recent high-profile efforts to challenge her on foreign policy issues.

Obama’s campaign manager was concerned enough this week to send out a detailed memo to nervous supporters assuring them that everything is just fine. The memo correctly points out that Obama posts better numbers in early-voting states, but so does former North Carolina Sen. John Edwards, which should earn the 2004 vice presidential nominee a test run to replace Obama as the main Clinton alternative. From the lower ranks of the Democratic contest, only New Mexico Gov. Bill Richardson is on the move in key state polls.

On the GOP side, the Iowa Republican Party’s straw poll on Saturday could shift the landscape a bit. The expected winner, former Massachusetts Gov. Mitt Romney, is the only top-tier candidate actually competing for it. Even so, a big Romney win in the 40 percent range could challenge former New York Mayor Rudy Giuliani’s frontrunner status in national polls and serve as another blow to Arizona Sen. John McCain’s stumbling candidacy.

Sen. Sam Brownback of Kansas and former Arkansas Gov. Mike Huckabee might do well, thanks to the Iowa social conservatives they’ve been passionately courting. And while some in the lower tiers, like former Wisconsin Gov. Tommy Thompson, could do so poorly that they leave the race, look for a surprise or two from the backbench.

Reps. Ron Paul of Texas and Tom Tancredo of Colorado are promising bets for straw-poll breakouts. But, of course, all bets are off until former Tennessee Sen. Fred Thompson formally enters the race as expected in early September and shows whether he can justify his summer-long run of effusive pre-campaign hype.