WASHINGTON -- Last year, Congress passed President Bush's 10-year, $1.35 trillion tax cut. This year, Bush tried but failed to make his tax cuts permanent.

The difference is control of the U.S. Senate. Missouri voters will help decide which party governs the Senate when they vote Nov. 5 for Democratic Sen. Jean Carnahan or Republican Jim Talent.

Several issues -- such as tax cuts or paying for prescription medicine for the elderly -- may be at stake. Then again, several may not.

"Because it's such a closely hung Senate, there really haven't been huge issues that have been decided upon, as we go into this election, where Missouri's Democratic senator has made the difference," said Dave Robertson, a political science professor at the University of Missouri-St. Louis.

Robertson was referring to the single-vote majority held by Democrats, and to Senate rules that frequently require 60 votes to pass a bill.

"Senators are so independent, it's hard to round up all those party doggies when it's time to have the big roundup," Robertson said.

At this point, the issue of Senate control has been more of an undercurrent in Missouri. Talent frequently mentions the importance of moving the president's agenda through Congress, but both candidates have focused mostly on introducing voters to their own accomplishments, ideas and experiences.

"We've always said this race is going to be decided by the candidates' records, and the issues Missourians talk about when they sit around their kitchen tables; jobs, education and health care," said Dan Leistikow, Carnahan's spokesman.

Would 'change the agenda'

However, he said party control makes the difference on issues involving prescription drugs, education and Social Security.

John Hancock, executive director of the Missouri GOP and an adviser to Talent, countered that party control is a critical argument: "It would fundamentally change the agenda, not just on specific votes, but it would literally change what votes are being considered."

Before control changed hands last summer, Republicans had a one-vote majority, too. At the time, the split was 50-50 with the Republican vice president casting tie-breaking votes. Then Vermont Sen. Jim Jeffords switched from Republican to independent and threw his support to the Democrats.

Jeffords, who supported Bush's tax cuts, waited to abandon the GOP until they had passed. Until his departure, Republicans had control of the entire lawmaking process, from the House to the Senate to the White House.

Arcane Senate budget rules mean the tax cuts will disappear in 2011, so Republicans in April tried to pass a permanent extension of the tax relief. Senate Democrats refused to even vote on a permanent extension.

They did vote on whether to permanently extend one popular component of Bush's tax plan, the repeal of estate taxes. Though she supported last year's tax cut, Carnahan voted against the estate tax measure, arguing it threatened retirement security programs. She favored a different proposal to eliminating the tax on estates worth less than $4 million.

Party control in the Senate made the difference on tax cuts. The narrow division has stalled agreement, at least for now, on a prescription drug plan. The parties are divided on whether the government should create its own insurance plan for medicine, which Democrats want, or whether it should rely on private insurers to provide coverage, as Republicans propose.