By using his nomination acceptance speech to say he would appoint Democrats to his cabinet and solicit Democratic policy ideas, presidential candidate John McCain sought to assure voters that he could avoid legislative gridlock if Democrats, as is likely, deepen their control of Congress.

The Republican's message is especially important this year, as polls show that Americans find both the president and Congress wanting and are frustrated with political bickering in Washington. Already, McCain advisers are working on strategies for governing, including emphasizing issues where Sen. McCain and Democrats largely see eye-to-eye, such as promoting renewable energy and curbing greenhouse-gas emissions. They say they would also try to break Democratic party unity on more-contentious issues. For example, they are counting on the growing ranks of Democratic centrists, who are more fiscally conservative than mainstream Democrats, to become McCain allies on taxes.

They're also counting on the legislative calendar to force accommodation. The tax cuts signed into law by President George W. Bush are set to expire at the end of 2010, and neither party wants to revert to higher rates across the board, especially given the frail economy. The Democrats, in general, want to raise the rates on families that make more than $200,000 in taxable income and use the money for other priorities, such as health-care subsidies. Sen. McCain wants to block any tax increases and reduce the top corporate tax rate to 25% from 35%. Neither is likely to prevail entirely, but they can't avoid working out their differences.

"Again and again, I've worked with members of both parties to fix problems that need to be fixed," the Arizona senator told the Republican convention. "That's how I will govern as president."

Most polls show Sen. McCain trailing Democratic presidential nominee Barack Obama by a small margin and forecast big gains for congressional Democrats, who already control the House and Senate. If Sen. McCain wins, a divided government probably wouldn't limit him greatly on foreign policy, where the president has broad powers to conduct war and diplomacy. But on economic and domestic policies, the consequences can be enormous. A President McCain would have to negotiate -- and compromise -- on his tax, energy, environment and health-care plans with the same Democratic lawmakers who are belittling his proposals on the campaign trail.