Player of the Week: Sen. John McCain (R-Ariz.)

Sen. John McCainJohn Sidney McCainDon’t disrespect McCain by torpedoing his clean National Defense Authorization Act Meghan McCain rips Trump's 'gross' line about her dad Trump's America fights back MORE (R-Ariz.) is in the thick of things this week.

McCain is a key surrogate for Mitt Romney’s presidential campaign, which has taken two steps forward, one step back over the last several months.

McCain’s backing has helped Romney in the Arizona GOP primary, which Romney is expected to win easily on Tuesday. Michigan, the state in which Romney grew up, presents a far more significant hurdle for the Republican front-runner.

As The Hill first reported, McCain opted to play kingmaker as he saw the Republican presidential primary unfold late last year. He and Romney waged a heated campaign against one another in 2008, but the Arizona senator embraced his former rival, partly because he thinks the other candidates are not electable.

It also helped Romney that McCain has butted heads with the other White House GOP hopefuls, most notably former Speaker Newt Gingrich (Ga.) and ex-Sen. Rick Santorum (Pa.).

McCain will also be heavily involved in policy this week. The top Republican on the Armed Services Committee has been urging the Obama administration to arm opposition forces in Syria as the government of Bashar al-Assad has continued its bloody crackdown on the protests engulfing the nation.

After President Obama defeated McCain in 2008, there was plenty of speculation that the two leaders would put aside their differences and work together on a wide variety of issues. That has not happened. Yet. Obama and McCain do agree that U.S. policy in Afghanistan should not change because of the rising violence there.

McCain said Sunday that the United States needs to “take the long view” in Afghanistan.

“If Afghanistan reverts to a chaotic situation, you will see al Qaeda come back and it again be a base, eventually, of attacks on the United States of America,” McCain said on CNN.

Other topics McCain will tackle this year include scheduled cuts to the Pentagon in 2013, the future of Iraq and U.S. aid to Egypt.