The defeat of longtime Sen. Richard Lugar in Indiana's Republican primary, coupled with the GOP-majority Senate's rejection of a bill needed to keep student-loan interest rates from doubling, raises valid questions about the party's allegiance to a tea-party agenda.

A number of political observers say Lugar's defeat Tuesday by Indiana state Treasurer Richard Mourdock had more to do with his age, 80, and his having lost touch with a state he hasn't lived in since first coming to Washington as a freshman senator in 1977.

But Rep. Pete Sessions (R., Texas), chairman of the National Republican Congressional Commitee, said Lugar's defeat was due to the same voter anger that birthed the tea-party movement.

"Whether you are in Indiana, North Carolina, and any number of states, it is ground zero for discontent," said Sessions. And the Republicans are counting on that discontent to be a huge factor in this fall's presidential election.

It's a good prediction that there will likely be a lot of irritable voters come November, but the Republican Party can't take for granted that none of that anger will be directed toward it — especially given the poor grades that members of Congress of both party persuasions are receiving.

The student-loan vote, in particular, has made a lot of voters angry at Congress, and they will remember who voted for what when they get their chance at the polls.

They will remember that GOP senators voted down a Democratic bill that would pay for lower interest rates by ending a tax break for the wealthy, and instead supported a Republican bill that would take the needed money from funds designated for preventive health programs.

Sessions believes his party has its fingers on the pulse of America, but before he bases that opinion on Lugar's defeat, he should check some other vital signs that voters are exhibiting.