Former Gov. Sarah Palin will announce today that she's hitting the campaign trail for Republicans -- including her former running mate John McCain. Palin, who did not campaign in last year's governor's races or in yesterday's Senate race in Massachusetts, has committed to contests in three states, including two Republican primaries, an aide said. She'll campaign in Texas for Gov. Rick Perry, who faces a primary challenge from Sen. Kay Bailey Hutchison; she'll appear in Arizona for Senator John McCain, who faces a challenge from the right; and she'll appear in Minnesota for Rep. Michelle Bachmann, a conservative firebrand who...