Since Democrats lost control of the House midway through President Barack Obama’s first term, both parties have parroted ready-made excuses for congressional gridlock.

Republicans blamed outgoing Senate Majority Leader Harry Reid and the Democrat-controlled Senate for stonewalling legislation; Democrats levied the same complaint at House Speaker John Boehner and House Republicans.

Enough with the excuses. With the GOP in control of both bodies of Congress, Republicans must show the party can govern. Texas lawmakers Sen. John Cornyn and Rep. Jeb Hensarling, both gaining power and influence in the new Congress, must step forward to help reshape the GOP from a party in opposition to a party in leadership.

We have long supported Cornyn, though we’ve criticized him for straying from his signature sound judgment and allowing the party’s extremists, including Texas’ junior senator, Ted Cruz, to set an agenda that feeds gridlock. As Senate majority whip, a post second only to new Majority Leader Mitch McConnell, Cornyn will have clout to provide crucial legislative leadership.

Cornyn’s first test could come on immigration reform, where mainstream Republicans, Democrats and the more radical wing of the GOP are at odds. We see a glimmer of hope, however. Cornyn opposed Obama’s executive order that shields millions in this country illegally from deportation — as did we — but Cornyn also recognizes the nation must reach a consensus on immigration reform by “finding parts that we agree on.”

He’s right. The party in the majority has an obligation to propose legislation that has a chance to pass the House and Senate and avoid a presidential veto.

Hensarling, who returns as chairman of the House Financial Services Committee, could provide clout to GOP efforts to reform the tax code. He has challenged his party to live up to free-market principles and to oppose “crony economy” that puts money and influence ahead of free enterprise and “the Main Street competitive economy.” While his efforts to reform market-distorting organizations like Fannie Mae, Freddie Mac and the Export-Import Bank are admirable, his greatest contribution could come in rewriting a complicated and badly broken tax code, which will go through his committee.

Regardless of what Congress does, the threat of a veto will loom. Obama has said he wants Congress to send him legislation that he can sign — until now a hollow request in a hopelessly divided Congress. GOP leaders must move forward with tax, immigration and other legislation and garner support from key Democrats and challenge the president to step up, too.