CEDAR RAPIDS, Iowa (AP) - Sen. Evan Bayh said Saturday Democrats shouldn't shy away from confronting President Bush on terrorism and national security because Republicans may be surprisingly vulnerable those issues.

"I believe for both substantive and political reasons we ought to take them on on that issue," Bayh said. "I believe they are vulnerable."

Bayh said Democrats have a long string of issues they can hammer on terrorism, including flawed intelligence and a botched handling of the war in Iraq.

"We can point out where this administration has let us down," he said. "We need to show we can be both tough and smart."

Bayh opened a three-day campaign swing in Iowa raising money for local Democrats and building the groundwork for a potential run for his party's presidential nomination.

He noted that in recent days top Republican strategists, ranging from White House aide Karl Rove to National GOP Chairman Ken Mehlman, have said their party will overtime to shift voter attention away from scandals in Congress and toward national security.

"It's pretty clear what they're going to do," Bayh said. "They think national security is their trump card."

A moderate Democrat who was governor of Indiana before being elected to the U.S. Senate in the predominantly Republican state, Bayh said combatting the war on terror is a basic issue Democrats must solve before voters will give the party any consideration.

"If the people of America don't trust us with their lives, they aren't likely to trust us with anything else," he said. "It's a threshold issue we have to cross, and frankly, we have had some weaknesses."

Bayh said some Democrats often deal with terrorism and national security by shifting attention to other issues.

"We can overcome the past, but not if we just try to change the subject," he said.

Bayh is part of a large and likely growing field of potential candidates seeking favor with party activists who are gearing up for the 2006 midterm election.

The conventional wisdom is this year will be a good one for Democrats because of the corruption scandals in Congress.

In addition, the party in the White House has historically suffered setbacks in elections held midway through their second term.

Bayh said Democrats have a series of hurdles to overcome including toughening the party's stance on terrorism and finding a coherent alternative message to the one being offered by Bush.

"When you don't have strong executive leadership, it's tough," he said. "When you're out of power, who speaks for the party?"

Bayh said the result often is many party leaders offering sometimes conflicting themes.

"We sound more like a cacophony than a coherent alternative," he said. "Too many Democrats may be sitting back and assuming Republican troubles will guarantee a solid year for us. We can't be a great party unless we're more than just not them."

Bayh has made it clear he's considering a run for the Democratic presidential nomination, but he said he's made no decision about what he'd do if Gov. Tom Vilasck also decided to run.

"I haven't made that decision," Bayh said. "If he runs, he'd be a very formidable candidate."

Bayh was raising money for local Democrats Saturday before moving on to help legislative candidates later in the weekend.

Although it's far too early for endorsements, he received considerable interest from party activists who said they were eager to find a candidate who can win in 2008.

"I think there's a curiosity among most of us about him," said former state lawmaker Bob Rush. "He looks to me to be one of the best and the brightest in our field."

State Rep. Swati Dandekar, D-Marion, said Bayh has clearly demonstrated solid political skills.

"He's a Democrat who can get elected in Indiana," she said. "Bush won in Indiana and Bayh won with a larger margin."

Signaling a long-term commitment to Iowa, Bayh planned to meet privately with Democratic legislators on Monday to determine how he can help in this year's election.