U.S. Sen. Mary Landrieu took aim Friday at her main opponent in her re-election bid, accusing U.S. Rep. Bill Cassidy of cowardice for refusing to participate in some televised debates and taking shots at his stances on Social Security and disaster funding.

Surrounded by about a dozen supporters holding signs asking “Where y’at Bill?” and comparing the congressman to the famously elusive characters Waldo and Carmen Sandiego, Landrieu, D-La., said she was “calling out” Cassidy, R-Baton Rouge.

“If he is too afraid to debate me, how in the heck is he going to be strong enough to stand up and fight for the people of our state, some of whom are actually in wheelchairs or children who can’t speak on their own behalf?” Landrieu asked in front of Dillard University, the site of the first televised Senate debate next week. “How is he going to fight for them? I have no idea.”

Landrieu and Rob Maness, another Republican in the race, have been critical of Cassidy’s refusal to participate in debates in recent weeks, including at a forum earlier this week in Kenner. While five televised debates for the candidates originally were scheduled, Cassidy has committed to take part in only two. That prompted one of the forums to cancel, though the others will continue without him.

In a brief news conference on a drizzly Friday morning, Landrieu said Cassidy also has skipped out on lower-profile events such as a forum with senior citizens in his hometown of Baton Rouge on Thursday. She contrasted that decision to a private fundraiser he held with former Republican presidential candidate Mitt Romney on Friday in New Orleans.

“He couldn’t find time to have lunch with them, but he has found time to have lunch with Mitt Romney today off of Jackson Square,” Landrieu said.

Asked about the debates, Cassidy’s spokesman dismissed the issue.

“Dr. Cassidy will be participating in two statewide televised debates,” campaign spokesman John Cummins said in an emailed statement. “Sen. Landrieu has been in office for 18 years and the voters are familiar with her Washington record. Sen. Landrieu prefers to interact with voters in highly scripted TV events that don’t require interacting with Louisianians. Bill Cassidy is busy driving across Louisiana as he meets and listens to as many citizens as possible across the state.”

Jabs about skipping debates are a time-honored election tradition, though they typically come from challengers looking to get name recognition and a wider audience for their views rather than from well-known incumbents. Indeed, state Treasurer John Kennedy used that tactic in his unsuccessful bid to unseat Landrieu six years ago in a campaign that eventually saw the two square off in four televised debates.

But in the tight Senate race in which the state’s increasingly rightward tilt favors Cassidy, many observers believe the congressman is trying to avoid forums that could lead to well-publicized gaffes, missteps or the airing of unpopular opinions.

Landrieu also used Friday’s event to hammer Cassidy on the issues. She accused the congressman of seeking to raise the age at which residents can receive full Social Security benefits from 67 to 70, a reference to votes he has cast in favor of budget resolutions that recommended putting such a plan into effect.

Landrieu noted that the average life expectancy in Louisiana is 75, only 72 for African-American residents and only 71 for African-Americans in Madison Parish.

“I guess Bill Cassidy thinks it’s OK for some people to work hard for 50 years and then only have one year when they collect Social Security that they paid into,” she said.

In response, the Cassidy campaign forwarded an August press release accusing Landrieu of voting to tax Social Security benefits and saying changes had to be made to keep the program solvent.

Landrieu on Friday also blasted Cassidy for voting against a measure that provided disaster recovery funds for Superstorm Sandy, which struck the Northeast in 2012, and Hurricane Isaac, which struck Louisiana the same year. At the time, Cassidy was pushing for the funds in that measure to be offset by decreases in spending elsewhere in the federal budget.

The senatorial candidates and independent groups have spent almost $18 million to run more than 50,000 TV ads in the state during the campaign, with about 65 percent of those spots coming from Democrats.

Still, Landrieu said, ads — particularly those paid for by outside groups — should not replace actual debate between the candidates.

“I would hope so, because if not, our democracy is going to be in serious trouble,” she said. “Let’s hope that debate and serious discourse can cut through the bogus ads that are on television.”

Follow Jeff Adelson on Twitter, @jadelson.